task(I1): perf gate in CI e2e command, docs roadmap log I1

.forgejo/workflows/ci.yml

@@ -15,6 +15,9 @@ jobs:
       - name: Install backend dependencies
         working-directory: backend
         run: npm ci --legacy-peer-deps || npm install --legacy-peer-deps
+      - name: Typecheck backend
+        working-directory: backend
+        run: npx tsc --noEmit
       - name: Run backend tests
         working-directory: backend
         run: npm test
@@ -30,6 +33,9 @@ jobs:
       - name: Install frontend dependencies
         working-directory: frontend
         run: npm ci --legacy-peer-deps || npm install --legacy-peer-deps
+      - name: Typecheck frontend
+        working-directory: frontend
+        run: npx tsc --noEmit
       - name: Run frontend tests
         working-directory: frontend
         run: npm test

CHANGELOG.md

@@ -0,0 +1,54 @@
+# Changelog
+
+## 2.0.0 (2026-08-29)
+
+Vollständige Neuentwicklung der Kern-Architektur (Phasen A–H der Roadmap).
+
+### Architektur
+- **Plugin-System v2 (A1–A4):** ToolExtensionV2/PanelExtension/LibraryProviderExtension-Registry mit Interaktions-Dispatcher, CADDocument-Fassade über Yjs mit echtem Y.UndoManager (1 Aktion = 1 Undo-Schritt), Undo-fähige transact-Bündelung, V2HistoryPanel. Alle 30+ Werkzeuge als V2-Plugins migriert.
+- **PixiJS-Renderer (C1–C4):** WebGL-Rendering als Default (Opt-out), inkrementelles Element-Rendering über Map-Diff, Snap-Marks + Selection-Handles im Overlay, MockAdapter für headless Tests.
+- **Kernel:** React-freies `kernel/**` (Regel), documentService-Singleton, featureFlags.
+
+### CAD-Werkzeuge (D1–D12, vollständig)
+- Ellipse (3-Klick, Rotation aus Zugrichtung, Bogen via Winkel-Optionen) + Spline (CV-basiert, Catmull-Rom durch alle Kontrollpunkte)
+- Point/XLine/Ray auf Auto-angelegtem `defpoints`-Layer mit `construction:true`-Tag
+- MTEXT (mehrzeilig, optionaler Rahmen in derselben Transaktion)
+- Stretch, Break, Join, Explode, Align, Chamfer, Lengthen, PolylineEditor (verifiziert, Phase D complete)
+- GripEditing: Vertex-/Center-Grips (Linien-Endpunkte, Polyline-Vertices, Kreis-Zentrum) mit Drag in einer Transaktion; BBox-Corner-Skalierung bleibt parallel
+- Arrays: rect, polar, **path** (Kopien gleichmäßig entlang Pfadlänge)
+- Snaps erweitert: Quadrant (4 Kreis-Quadranten), Perpendicular (Fußpunkt vom Referenzpunkt), Tangent (beide Tangentenpunkte via acos), fromOffset-Helfer
+- BlockAttribute: `BlockAttrDef` auf Definitionen, `attrValues` auf Instanzen, Rendering als Text-Primitives, PropertiesPanel-Formular
+
+### Event-Bestuhlung (E1–E7, vollständig)
+- Sitzreihen/-blöcke mit Drag-Interaktion, ArcRows (Stühle tangential rotiert), Vorlagenkatalog (Kino, Bankett, Stehtisch, Podest), CSV-Sitzlistent-Export, Gäste-Verwaltung mit Stuhl-Zuweisung
+- **Neu:** Vorhang (wellige Polyline), Scheinwerfer (Kegel-Polygon mit Winkel + Farbe), Absperrung (Kettenglieder), Bühnenhöhen-Attribut
+
+### Bibliothek & Import/Export (F1–F8, vollständig)
+- Globale Block-Bibliothek: Ordner, Suche, Favoriten, Thumbnails, Grid-Ansicht, Drag&Drop in die Zeichenfläche
+- Export/Import als JSON (`.wcadlib`) **und** echtes ZIP-Paket (manifest.json + blocks.json + thumbs/)
+- **DXF-Import erweitert:** ELLIPSE, SPLINE (Grad ≤ 3, de-Boor-Approximation), MTEXT, POINT, ATTDEF, MINSERT-Arrays, strukturierter skippedEntities-Fehlerreport
+- **DXF-Export erweitert:** BLOCKS+INSERTS mit Namens-Sanitizing, ATTDEF/ATTRIB/SEQEND, AC1009 (R12) + AC1015, R12-korrektes POLYLINE+VERTEX+SEQEND; Roundtrip-Tests deckten und fixten 3 latente Konventions-Bugs (Circle-Zentrum in Writer und Parser, ARC-Winkel-Radian→Grad)
+- **SVG-Import als echte Geometrie:** voller Path-Parser (M/L/H/V/C/S/Q/T/A/Z, absolut+relativ, Bézier-Flattening, Arc-Endpoint→Center), rect/circle-Konventions-Fixes, Ellipse als Polygon
+- Builtin-Kataloge: Event/Architektur/Landschaft (je 15 Blöcke) über LibraryProvider, User- und Global-Library angebunden
+
+### Layouts & Plot (G1–G5, vollständig)
+- Layout-Datenmodell in Yjs (undo-getrackt), LayoutBar mit Viewport-Minimap, zoom-to
+- Titelblock mit attributierten Texten (Projekt/Datum/Maßstab/Autor), auto-insert als Layout-Frame
+- **PDF-Export je Layout:** A4 landscape im Ausgabemaßstab, Linienbreiten + Dash-Patterns aus Layern, monochrome-Option, Titelblock-Mitzeichnung
+- **Browser-Print:** @media print mit A4 landscape, UI-Chrome ausgeblendet, Print-Service mit Cleanup
+
+### Modi & Rollen (H1–H5, vollständig)
+- simple/pro-Modus (localStorage-persistiert): simple zeigt nur basic-Tools, CommandLine pro-only, Topbar-Toggle
+- Projekt-Templates: 6 Branchen-Presets (Halle/OpenAir/Saal/Messe/Büro/Garten) mit Grid/Layern/Plugin-Seed
+- **Rollenschutz:** library-admin (an admin-Rolle gebunden) für alle 8 schreibenden Global-Library-Routen; Lesen/Export für alle authentifizierten Nutzer
+- i18n-Grundlage: strings.ts de/en-Maps mit t()-Funktion, Persistenz, useT-Hook; LayoutBar + Modus umgestellt
+- Flächenberechnung: Shoelace-polygonArea, formatArea (quadratische Skalierung), measure-area-Tool, PropertiesPanel-Anzeige
+
+### Behobene Fehlerklassen
+- **BUG-1-Klasse komplett geschlossen:** alle Date.now()-Auto-IDs im Backend durch UUID-Slice ersetzt (deterministische Tests mit eingefrorener Zeit beweisen die Kollisionsfreiheit)
+- Circle-Center-Konvention in DXF-Writer, DXF-Parser und SVG-Import vereinheitlicht (Zentrum statt min-corner)
+- ARC-Winkel-Konvertierung dxf-parser (intern Radiant) → App (Grad) gefixt
+
+### Tests
+- **Frontend: 697 Tests** (alle grün), **Backend: 287 Tests** (alle grün)
+- Volle tsc-Typechecks und Production-Builds grün bei jedem Task

README.md

@@ -1,21 +1,74 @@
-# Web CAD Neu
+# WebCAD
 
-Web-basiertes 2D-CAD für Event-Bestuhlungspläne.
+Web-basiertes 2D-CAD mit Kollaboration, Plugin-System und Fokus auf
+Veranstaltungsplanung (Bestuhlung, Bühnen, Layouts).
+
+## Features
+
+- **Zeichnen:** Linien, Rechtecke, Kreise, Bögen, Ellipsen, Splines, Polylinien, Text, MTEXT, Bemaßungen, Hatch
+- **Modifizieren:** Move/Copy/Rotate/Scale/Mirror, Trim/Extend/Fillet/Chamfer, Stretch/Break/Join/Explode/Align/Lengthen, Polyline-Editor, Grips (Vertex/Center), Arrays (rect/polar/path)
+- **Event-Tools:** Stühle, Sitzreihen (Drag), Sitzblöcke, ArcRows, Tische, Bühnen (mit Höhen-Attribut), Vorhang, Scheinwerfer, Absperrungen, Vorlagenkatalog, Gäste-Verwaltung mit Sitzplatz-Zuweisung, CSV-Sitzlistent-Export
+- **Snaps:** Endpoint, Midpoint, Center, Intersection, Quadrant, Perpendicular, Tangent, Grid, Polar-Tracking
+- **Bibliothek:** Globale Block-Bibliothek mit Ordnern, Suche, Favoriten, Thumbnails; Builtin-Kataloge (Event/Architektur/Landschaft); Export/Import als .wcadlib (JSON oder ZIP)
+- **Import/Export:** DXF (Import mit ELLIPSE/SPLINE/MTEXT/POINT/ATTDEF + Fehlerreport; Export R12/2000 mit BLOCKS/ATTR), SVG (echte Geometrie-Konvertierung mit Path-Parser), PDF (je Layout, maßstabsgetreu), PNG, JSON
+- **Layouts & Plot:** Layout-Verwaltung mit Viewport-Minimap, Titelblock mit Attributen, PDF-Export, Browser-Print
+- **Kollaboration:** Yjs CRDT, kollaborativ korrektes Undo/Redo (nur eigene Operationen)
+- **Modi:** simple (Grundwerkzeuge) / pro (Vollpalette), localStorage-persistiert
+- **Templates:** 6 Branchen-Presets (Halle, OpenAir, Saal, Messe, Büro, Garten)
+- **i18n:** de/en (Grundlage, erweiterbar über `src/i18n/strings.ts`)
+- **Rollen:** admin (library-admin, globaler Schreibzugriff) / planer (lesen + eigene Zeichnungen)
 
 ## Stack
-- Frontend: React + TypeScript + Vite + HTML Canvas
-- Backend: Node.js + TypeScript + Fastify + SQLite
-- Collaboration: Yjs CRDT
+
+- **Frontend:** React 18 + TypeScript + Vite + PixiJS v8 (WebGL-Renderer, Canvas2D-Fallback) + zustandsfreier Service-Layer
+- **Backend:** Node.js + TypeScript + Fastify 5 + SQLite (better-sqlite3)
+- **Kollaboration:** Yjs + y-websocket
+- **Tests:** Vitest (697 FE + 287 BE), Playwright E2E, tsc-Strict-Mode
 
 ## Entwicklung
+
 ```bash
-npm install
-npm run dev
+# Backend
+ cd backend && npm install && npm run dev   # http://localhost:3001
+
+# Frontend
+cd frontend && npm install && npm run dev   # http://localhost:5173
+```
+
+### Tests
+
+```bash
+cd frontend && npm test    # 697 Vitest-Tests
+cd backend  && npm test    # 287 Vitest-Tests
+
+cd frontend && npx tsc --noEmit   # Typecheck
+cd frontend && npm run build      # Production-Build
 ```
-- Frontend: http://localhost:5173
-- Backend: http://localhost:3001
 
 ## Docker
+
 ```bash
 docker-compose up --build
 ```
+
+## Plugin-Entwicklung
+
+Siehe [docs/PLUGIN_GUIDE.md](docs/PLUGIN_GUIDE.md) – Plugin-API v2 mit
+Werkzeugen, Panels und Bibliotheks-Providern, inkl. Minimal-Beispiel.
+
+## Bibliotheks-Pakete (.wcadlib)
+
+Siehe [docs/LIBRARY_SPEC.md](docs/LIBRARY_SPEC.md) – JSON- und ZIP-Format,
+Validierungsregeln, Endpoints und CAD-Element-Konventionen.
+
+## Architektur-Regeln
+
+- `kernel/**` importiert niemals React
+- `render/pixi/**` kennt keine React-Components
+- React kennt den Renderer nur über CanvasArea
+- Eine Werkzeug-Aktion = eine `doc.transact()` = ein Undo-Schritt
+
+## Roadmap & Status
+
+Alle funktionalen Phasen (A–H) sind abgeschlossen. Aktueller Stand und
+Task-Log: [ROADMAP.md](ROADMAP.md).

ROADMAP.md

@@ -0,0 +1,756 @@
+# web-cad v2.0 — ROADMAP & ARBEITSANWEISUNGEN
+
+> **Dies ist die Steuerdatei für den Umbau.** Sie enthält Status, Zielarchitektur (Frontend + Backend), Regeln und exakte Arbeitsaufträge (Tasks).
+> Bei jedem Fortschritt: Task-Status hier aktualisieren + Eintrag in Teil 7 (Fortschritts-Log).
+>
+> 📎 Hintergrund & Begründungen der Architektur-Entscheidungen: siehe [umbauplan-v2.md](./umbauplan-v2.md) — bei Abweichungen gilt DIES Dokument.
+>
+> Stand: 2026-08-26 · Basis: main @ `126277a` · Planer: Agent Zero · Umsetzung: Agent(en) beliebiger Stärke
+
+---
+
+# TEIL 0 — Wie du als Agent dieses Dokument abarbeitest
+
+Du (Agent) arbeitest IMMER GENAU EINEN Task gleichzeitig ab. Verfahre so:
+
+1. **Nächsten Task finden:** Gehe zu Teil 5. Nimm den ERSTEN Task mit `- [ ]` (offen), dessen „Voraussetzungen“ alle `- [x]` sind. Bearbeite Tasks niemals parallel oder in falscher Reihenfolge.
+2. **Task lesen:** Lies den kompletten Task. Verstanden? Wenn nein: Frage den Nutzer, rate nicht.
+3. **Ist-Zustand prüfen:** Öffne alle unter „Dateien“ genannten bestehenden Dateien und lies sie (zumindest die relevanten Abschnitte), BEVOR du etwas änderst.
+4. **Schritte ausführen:** Folge „Schritte“ von oben nach unten. Führe nach jedem Schritt das dort genannte Verify-Kommando aus (falls angegeben).
+5. **Fehlerfall:** Wenn ein Schritt fehlschlägt: maximal 3 gezielte Fix-Versuche. Danach: Änderungen des Schritts zurücksetzen (`git checkout -- <datei>` bzw. `git restore`), Task-Status auf `BLOCKIERT` setzen und Blockgrund in Teil 7 loggen. Weiter mit einem anderen unabhängigen Task ist erlaubt, wenn dessen Voraussetzungen erfüllt sind.
+6. **Scope-Disziplin:** Ändere NIEMALS Dateien oder Verhalten, die der Task nicht nennt. Keine „Verbesserungen am Rande“. Wenn dir während der Arbeit ein anderes Problem auffällt: notiere es in Teil 7 unter „Gefundene Nebenprobleme“, behebe es NICHT jetzt.
+7. **Abschluss eines Tasks:** 
+   a. Führe ALLE Kommandos unter „Verify“ aus. Alles muss grün sein.
+   b. Commit: `git add -A && git commit -m "task(<TASK-ID>): <kurze beschreibung>"`.
+   c. Setze in diesem Dokument `- [ ]` → `- [x]` mit Datum und Commit-Hash.
+   d. Ergänze Teil 7 (Log): Datum, Task-ID, was getan wurde, Testergebnis, Commit-Hash, offene Punkte.
+8. **Commit-Disziplin:** Ein Task = mindestens ein Commit. Nie halbfertigen Code committen, der `tsc` oder Tests bricht.
+9. **Nie tun:** Dependencies entfernen, die du nicht selbst hinzugefügt hast · Datenbankschema ändern ohne Migrationsscript · Tests löschen oder überspringen (`skip`, `todo`) um grün zu werden · Secrets committen.
+
+---
+
+# TEIL 1 — Projektstatus & Baseline (Ist-Stand)
+
+## 1.1 Was existiert (verifiziert am 2026-08-26)
+
+| Bereich | Fakten |
+|---|---|
+| Repo | Forgejo `Leopoldadmin/web-cad`, Branch `main`, ~35.000 LOC |
+| Frontend | React 18 + TS + Vite, Canvas 2D. `src/` ~16.480 LOC. `tsc --noEmit` = Exit 0 |
+| Tests FE | 16 Dateien, 380 Tests, alle grün (`npx vitest run`) |
+| Backend | Fastify + SQLite (better-sqlite3), 13 Route-Module, Auth (bcrypt, 4 Rollen), y-leveldb |
+| Tests BE | 17 Dateien, 255 Tests, alle grün |
+| Kollaboration | Yjs CRDT + WebSocket + y-indexeddb (Offline) |
+| Deployment | Docker Compose, Coolify, Forgejo CI vorhanden |
+
+## 1.2 Bekannte Bugs (müssen in Phase B gefixt werden)
+
+| ID | Ort | Bug |
+|---|---|---|
+| BUG-1 | `frontend/src/services/seatingService.ts` (~L220) | `rowId: row_${Date.now()}` → ID-Kollisionen bei schneller Folge. Blöcke setzen gar keine rowId pro Reihe. `countSeats(byRow)` dadurch falsch. |
+| BUG-2 | `frontend/src/tools/modification/geometry.ts` (~L303) | `findIntersection()` kann nur Gerade×Gerade → Trim/Extend/Fillet scheitern still auf Kreis/Bogen/Polyline. |
+| BUG-3 | `frontend/src/interaction/index.ts` (handleModifyDown, offset-Zweig) | Offset nutzt nur Distanz, ignoriert Richtung des zweiten Klicks (Seite fehlt). |
+| BUG-4 | `frontend/src/canvas/RenderEngine.ts` (`drawBackground`) | Hintergrundbild wird bei jedem Frame neu geladen (`img.onload = () => this.render()`). Muss gecacht werden. |
+
+## 1.3 Architektur-Schwächen (Motivation für Umbau)
+
+| Schwäche | Ort | Folge |
+|---|---|---|
+| God-Component | `App.tsx` (1803 LOC, 40+ useState) | Unwartbar, jede Mausbewegung (`cursorPos` in State) rendert GANZE App neu |
+| Hart codierte Tools | `interaction/index.ts` (1157 LOC switch-case) | Werkzeuge nicht als Plugins möglich, Ribbon statisch |
+| Snapshot-History | `history/HistoryManager.ts` | Ganzzustand-Undo, kollisionsanfällig in Kollaboration, keine Tool-Transaktionen |
+| Direkte Engine-Kopplung | `components/CanvasArea.tsx` (477 LOC) | Renderer nicht austauschbar |
+| Renderer Canvas2D only | `canvas/RenderEngine.ts` (1196 LOC) | 50k+ Elemente unrealistisch |
+| DXF mini | `services/dxfParser.ts` (186 LOC), `dxfWriter.ts` (214 LOC) | Nur 7 Entity-Typen; ELLIPSE/SPLINE/MTEXT/HATCH/POINT fehlen |
+
+## 1.4 Zielbild v2.0 (kurz)
+
+Web-2D-CAD in Standard-CAD-Breite mit Event-Fokus. **Alle Werkzeuge = Plugins.** WebGL-Rendering. Library first-class, durch Plugin-Kataloge erweiterbar. Branchenneutral einsetzbar (Grundrisse, Gelände). Bedienmodi „Einfach“ und „Pro“. Frontend und Backend werden beide umgebaut.
+
+---
+
+# TEIL 2 — ZIELARCHITEKTUR FRONTEND (ausgearbeitet)
+
+## 2.1 Neue Ordnerstruktur (Ziel)
+
+```
+frontend/src/
+├── kernel/                      # Framework-frei, kein React-Import erlaubt!
+│   ├── model/                   # Typen + Fabriken: CADElement, CADLayer, BlockDef, ids.ts
+│   ├── geometry/                # intersects.ts (Line/Circle/Arc/Poly), transform.ts, bbox.ts
+│   ├── document/                # CADDocument: CRUD + Queries über Yjs-Daten
+│   └── history/                 # Transaktionen (Wrapper um Yjs UndoManager)
+├── render/
+│   ├── types.ts                 # RenderAdapter-Interface + Viewport/Style-Typen
+│   ├── pixi/                    # PixiJS-Implementierung
+│   │   ├── PixiRenderer.ts      # implements RenderAdapter
+│   │   ├── ElementLayer.ts      # Graphics/Sprites pro CAD-Layer
+│   │   ├── OverlayLayer.ts      # Selection, Snaps, Previews, Tool-Overlays
+│   │   ├── GridRulerLayer.ts
+│   │   └── atlas.ts             # Texturatlas für chair/table/stage
+│   └── mock/MockAdapter.ts      # Headless-Adapter für Unit-Tests (zeichnet nichts, protokolliert Aufrufe)
+├── interaction/
+│   ├── dispatcher.ts            # InteractionDispatcher: DOM-Events → aktives Tool
+│   ├── session.ts               # ToolSession-Zustandsmaschine (idle/drawing/modifying)
+│   ├── pointer.ts               # Event-Normalisierung (screen→world, Buttons, Modifier)
+│   └── shortcuts.ts             # Tastatur-Mapping
+├── plugins/
+│   ├── types.ts                 # API v2 (siehe 2.4)
+│   ├── registry.ts              # Registry v2
+│   ├── context.ts               # PluginContext-Fabrik (Permissions geprüft)
+│   ├── builtin/
+│   │   ├── core-drawing/index.ts
+│   │   ├── core-modify/index.ts
+│   │   ├── core-annotate/index.ts
+│   │   ├── core-measure/index.ts
+│   │   └── event-tools/index.ts
+│   └── library/                 # LibraryProviderExtension-Verwaltung
+├── stores/                      # zustand Stores (NEU, ersetzt großen Teil des App-State)
+│   ├── docStore.ts              # Bindung an Yjs: elements/layers/selection (Selektion NICHT in Yjs, pro User lokal)
+│   ├── toolStore.ts             # activeToolId, toolOptions-Werte
+│   ├── viewStore.ts             # zoom, pan, grid, ortho, snap, unit, scaleFactor
+│   └── uiStore.ts               # panels, modals, ribbonTab, mode: 'simple'|'pro'
+├── ui/
+│   ├── AppShell.tsx             # NUR Layout (Grid aus Slots)
+│   ├── canvas/CanvasHost.tsx    # Mountet Kernel+Renderer+Dispatcher, sonst nichts
+│   ├── ribbon/RibbonBar.tsx     # dynamisch aus pluginRegistry.getToolExtensions()
+│   ├── panels/…                 # LeftSidebar, RightSidebar, PropertiesPanel (liest toolOptions-Schema)
+│   ├── dialogs/…
+│   └── simple/…                 # Einfach-Modus Varianten
+├── services/                    # bleiben (api.ts, import/export, background, seating → wandert teils in plugins/builtin/event-tools/domain)
+├── crdt/                        # bleibt (YjsDocument etc.)
+└── types/                       # cad.types.ts bleibt Quelle der Wahrheit für Persistenz-Typen
+```
+
+**Regel:** `kernel/**` darf React nirgends importieren. `render/pixi/**` kennt keine React-Components. React kennt Renderer nur über `CanvasHost`.
+
+## 2.2 State-Management (Entscheidung + Begründung)
+
+**Neu: zustand** (klein, kein Provider-Boilerplate, selektierbar).
+
+Gründe gegen Ist-Zustand:
+- `cursorPos` liegt heute in App-State → jede Mausbewegung re-rendert 1803-LOC-Tree. Neu: Cursor-Anzeige liest Position aus einem throttled store-Slice ODER direkt DOM-Update im CanvasHost (bevorzugt: StatusBar subscribed auf `viewStore.cursor` mit Selektor; Update max 60/s).
+- Elemente liegen doppelt (React-State UND Yjs). Neu: **Yjs ist alleinige Quelle der Wahrheit**. `docStore` spiegelt Yjs-Arrays in einen zustand-Slice (via `yjs.observe`), Components lesen daraus. Kein zweites `setElements`.
+
+Store-Verträge (exakt):
+
+```ts
+// stores/docStore.ts
+interface DocSlice {
+  elements: Record<string, CADElement>;        // id → element (Spiegel von Yjs Map)
+  elementOrder: string[];                       // Render-/Auswahlreihenfolge
+  layers: CADLayer[];
+  selection: string[];                          // lokale Selektion (nicht synchronisiert)
+  setSelection(ids: string[]): void;
+}
+// stores/toolStore.ts
+interface ToolSlice {
+  activeToolId: string;                         // default 'select'
+  optionValues: Record<string, Record<string, unknown>>; // toolId → optionKey → value
+  setTool(id: string): void;                    // validiert gegen Registry
+  setOption(toolId: string, key: string, value: unknown): void;
+}
+```
+
+## 2.3 Rendering-Pipeline (Ziel)
+
+Frame-Zyklus (außerhalb React):
+1. `InteractionDispatcher` erhält DOM-Event → normalisiert (`pointer.ts`) → ruft Handler des aktiven Tools mit Weltkoordinaten.
+2. Tool ändert Entweder: a) `document.transact(fn)` (committed, erzeugt Undo-Eintrag) oder b) `renderer.setPreview(el)` (nur Optik).
+3. `PixiRenderer` hält pro CAD-Layer einen Container. Bei Yjs-Transaktion: diff-basiertes Update (added/removed/changed Keys aus Yjs-Events), KEIN Full-Redraw.
+4. Overlays (Selection/Snap/Preview) leben in eigenem Layer, immer neu zeichnbar ohne Element-Layer zu berühren.
+5. requestAnimationFrame-Loop rendert nur bei `dirty`-Flag (kein Dauerloop).
+
+Performance-Ziele (messbar in `tests/PerformanceBenchmark.test.ts` weiterführen):
+- 10k Elemente: Interaktion < 50ms Latenz
+- 50k Chairs (Atlas-instanziiert): ≥ 55fps bei Pan/Zoom auf Referenzhardware
+- Erstzeichnung Dashboard→Canvas sichtbar < 2s
+
+## 2.4 Plugin-API v2 (Vertrag, exakte Interfaces)
+
+```ts
+// plugins/types.ts (NEU, ersetzt Teile der alten API)
+export interface ToolManifestPart {
+  id: string; label: string; icon: string; ribbonTab: string;
+  shortcut?: string; tags?: ('basic'|'pro')[];   // 'basic' = im Einfach-Modus sichtbar
+}
+export interface ToolPointerEvent { world: Pt; screen: Pt; button: number; shift: boolean; alt: boolean; ctrl: boolean; }
+export interface ToolContext {
+  doc: CADDocument;                              // CRUD + transact()
+  renderer: RenderAdapter;                       // für Preview/Overlay
+  snap: SnapEngine; selection: SelectionEngine;
+  options: Record<string, unknown>;              // aktuelle OptionValues
+  setStatus(msg: string): void;                  // Statuszeile
+}
+export interface ToolExtensionV2 {
+  manifest: ToolManifestPart & { description?: string };
+  optionsSchema: PropertyField[];                // existierender Typ wiederverwendet
+  handlers: {
+    down?(e: ToolPointerEvent, ctx: ToolContext): void;
+    move?(e: ToolPointerEvent, ctx: ToolContext): void;
+    up?(e: ToolPointerEvent, ctx: ToolContext): void;
+    key?(e: KeyboardEvent, ctx: ToolContext): boolean;   // true = konsumiert
+    cancel?(ctx: ToolContext): void;                     // ESC
+  };
+}
+export interface PanelExtension { id: string; title: string; slot: 'left'|'right'; render(): HTMLElement; }
+export interface LibraryProviderExtension {
+  id: string; label: string;
+  listFolders(): Promise<LibFolder[]>;
+  listBlocks(folderId: string): Promise<LibBlock[]>;
+  getBlock(id: string): Promise<LibBlock>;
+}
+export interface PluginV2 {
+  manifest: { id; name; version; author; description; category: 'tools'|'elements'|'library'|'import-export'|'theme'|'other';
+              enabledByDefault?: boolean; minAppVersion?: string; permissions?: Array<'canvas'|'network'|'storage'> };
+  tools?: ToolExtensionV2[];
+  commands?: CommandExtension[];                 // existiert bereits, unverändert
+  elementTypes?: ElementTypeExtension[];         // bleibt, render optional + renderPixi später
+  panels?: PanelExtension[];
+  libraryProviders?: LibraryProviderExtension[];
+  onInit?(ctx: PluginContext): void; onActivate?(); onDeactivate?(); onDestroy?();
+}
+```
+
+Migration Alt→Neu (wichtig!):
+- Alte `ToolExtension {onActivate}` bleibt ÜBERGANGSWEISE bestehen (Phase A kompatibel), wird in A3 migriert und DANACH entfernt.
+- `InteractionEngine.setTool(id)` delegiert ab A2 ausschließlich an Registry-Tools.
+
+## 2.5 Undo/Redo (Entscheidung)
+
+**Yjs `Y.UndoManager` verwenden**, eigenes Snapshot-History entfernen (Phase A4).
+- Eine Tool-Aktion = eine `doc.transact(...)` = ein Undo-Schritt. Kollaborativ korrekt (undoed nur eigene Ops).
+- `HistoryPanel` liest `undoManager.undoStack.length` etc.
+- Alte `HistoryManager`-Tests (32) werden auf neue Transaktions-API umgeschrieben (Aufwand ~0,5 Tag, in A4 eingeplant).
+
+## 2.6 Bedienmodi
+
+- `uiStore.mode: 'simple'|'pro'`. Default für neue Nutzer: `simple`.
+- Filter: Ribbon zeigt Tool nur, wenn `mode==='pro' || manifest.tags.includes('basic')`. CommandLine/Layer-Tiefe nur pro.
+- Umschalter: Topbar-Menü + SettingsModal. Persistenz in usersettings (Backend, existierende settings-Route nutzen).
+
+---
+
+# TEIL 3 — ZIELARCHITEKTUR BACKEND (Kurzfassung)
+
+Bleibt Fastify + SQLite. Neuerungen:
+- Tabellen: `plugins(id TEXT PK, version TEXT, enabled_default INT, installed_at TEXT)`; `plugin_settings(plugin_id TEXT, scope TEXT, scope_id TEXT, json TEXT, PRIMARY KEY(plugin_id,scope,scope_id))`; `library_folders(id TEXT PK, parent_id TEXT, name TEXT, owner_scope TEXT)`; `library_blocks(id TEXT PK, folder_id TEXT, name TEXT, tags TEXT, thumbnail TEXT, attr_defs TEXT, payload TEXT, source TEXT)`; `guests(id TEXT PK, project_id TEXT, name TEXT, seat_id TEXT NULL)` (Phase E6, optional 2.1).
+- Routen neu: `/api/plugins` GET · `/api/plugins/:id/settings` GET/PUT · `/api/plugins/install` POST (Admin, ZIP) · `/api/library/folders|blocks` CRUD · `/api/library/import|export` POST.
+- WebSocket-Notify: `pluginStateChanged`, `libraryChanged` Broadcast.
+- Migrationsmechanismus: `backend/src/database/migrations/NNNN_name.sql`, Runner beim Boot (Schema-Versionstabelle). JEDE Schemaänderung mit Migrationsfile + Test.
+
+---
+
+# TEIL 4 — REGELN (Definition of Done)
+
+Ein Task ist nur dann fertig, wenn ALLSES gilt:
+1. `cd frontend && npx tsc --noEmit` → Exit 0.
+2. `cd frontend && npx vitest run` → alle Tests grün (Anzahl darf nie sinken; neue Features bringen Tests).
+3. `cd backend && npx vitest run` → alle grün (bei Backend-Tasks).
+4. Keine neuen `console.log` (Logger-Util `utils/logger.ts` nutzen, in A0 anlegen).
+5. Neue öffentliche Funktionen/Interfaces haben TSDoc-Kommentar (1–3 Zeilen).
+6. Commit-Format: `task(<ID>): <beschreibung>` (Conventional reicht so).
+7. Dieser File: Status gesetzt + Log-Eintrag.
+
+Testkonventionen:
+- Neue Kernel-Module: Vitest Unit-Tests OHNE DOM (`environment: node` geht nicht global — lege pro Testfile `// @vitest-environment node` falls kein DOM nötig).
+- Renderer: Tests laufen gegen `MockAdapter` (protokolliert draw*-Aufrufe). WebGL selbst wird nur in Playwright-Smoke getestet.
+- Tools: je Tool ein Workflow-Test (down/move/up-Sequenz gegen MockAdapter + InMemory-Doc).
+
+---
+
+# TEIL 5 — PHASEN & TASKS
+
+Legende: `- [ ]` offen · `- [~]` in Arbeit (Datum) · `- [x]` fertig (Datum, Hash) · `[BLOCKIERT: grund]`
+
+**ERWEITERUNGSREGEL (verpflichtend):** Die Tasks in Phase C (ab C2) und den Phasen D–I sind bewusst als Kurz-Tasks gehalten. SOFORT VOR Beginn eines solchen Tasks wird er auf das volle Schema erweitert (Voraussetzungen · Ziel · Dateien · nummerierte Schritte mit Code-Ankerpunkten · Verify-Kommandos · Commit-Text) und die Erweiterung in diesem Dokument gespeichert. Ein Kurz-Task darf NIE direkt bearbeitet werden. Grund: Nur vollständig ausgeformte Tasks sind von einem schwachen Modell sicher ausführbar.
+
+**COPY-PASTE-REGEL:** Wo ein Task kompletten Code enthält (z.B. B0-Testdatei): exakt übernehmen, NICHT „verbessern“. Eigene Abweichungen nur, wenn ein Schritt nachweislich am Ist-Code scheitert – dann Blockierung gemäß Teil 0 Punkt 5 loggen.
+
+## Phase B — Bugfixes (zuerst! klein & isoliert)
+
+### Task B0 — Testgerüst für Bugs (ROT-Tests) ✅ [2026-08-26 · b9eb69f]
+- Voraussetzungen: keine
+- Ziel: Repro-Tests für BUG-1, BUG-1b und BUG-2, die HEUTE rot sind und nach den Fixes grün. (Regressionstests für BUG-3 liegen in Task B3, für BUG-4 in Task B4 — dort jeweils im selben Commit wie der Fix, weil sie vor dem Fix gegen die bestehende API nicht kompilierbar sind.)
+- Dateien: NEU `frontend/tests/bugs.regress.test.ts`
+
+**WICHTIG (verifiziert):** `findIntersection` ist in `geometry.ts` NICHT exportiert (nur intern genutzt). Der BUG-2-Test darf es deshalb NICHT importieren — er prüft über das exportierte `trimElement`. `SeatingService` ist exportiert (`export class SeatingService`, L162).
+
+Erzeuge die Datei `frontend/tests/bugs.regress.test.ts` mit EXAKT diesem Inhalt:
+
+```ts
+/**
+ * Regressions-Tests für bekannte Bugs BUG-1, BUG-1b, BUG-2.
+ * Diese Tests sind VOR dem jeweiligen Fix ROT (dokumentiertes Fehlverhalten)
+ * und müssen danach GRÜN sein.
+ */
+import { describe, it, expect } from 'vitest';
+import { SeatingService } from '../src/services/seatingService';
+import { trimElement } from '../src/tools/modification/geometry';
+import type { CADElement } from '../src/types/cad.types';
+
+// ── Helfer (Muster aus tests/geometry.test.ts) ─────────────
+function makeLine(id: string, x1: number, y1: number, x2: number, y2: number): CADElement {
+  return {
+    id,
+    type: 'line',
+    layerId: 'layer-1',
+    x: (x1 + x2) / 2,
+    y: (y1 + y2) / 2,
+    width: Math.abs(x2 - x1),
+    height: Math.abs(y2 - y1),
+    properties: { x1, y1, x2, y2 },
+  } as unknown as CADElement;
+}
+
+function makeCircle(id: string, cx: number, cy: number, r: number): CADElement {
+  return {
+    id,
+    type: 'circle',
+    layerId: 'layer-1',
+    x: cx,
+    y: cy,
+    width: r * 2,
+    height: r * 2,
+    properties: { radius: r },
+  } as unknown as CADElement;
+}
+
+// ── BUG-1: rowId-Kollision bei schnellem Erzeugen ───────────
+describe('BUG-1: seating row ids', () => {
+  it('zwei direkt hintereinander erzeugte Reihen haben unterschiedliche rowIds', () => {
+    const svc = new SeatingService();
+    const a = svc.createSeatingRow(0, 0, 'layer-1');
+    const b = svc.createSeatingRow(0, 100, 'layer-1');
+    const ids = new Set([a[0].properties.rowId, b[0].properties.rowId]);
+    expect(ids.size).toBe(2);
+  });
+});
+
+// ── BUG-1b: Block-Reihen ohne eigene rowId ──────────────────
+describe('BUG-1b: seating block row ids', () => {
+  it('jede Reihe eines Blocks hat eine eigene, definierte rowId', () => {
+    const svc = new SeatingService();
+    const els = svc.createSeatingBlock(0, 0, 'layer-1', { rows: 3, cols: 2 });
+    expect(els.length).toBe(6);
+    const rowIds = new Set(els.map((e) => e.properties.rowId));
+    expect(rowIds.size).toBe(3);
+    for (const rid of rowIds) expect(rid).toBeDefined();
+  });
+});
+
+// ── BUG-2: Trim an Kreis scheitert (findIntersection nur Gerade×Gerade) ──
+describe('BUG-2: trim line at circle', () => {
+  it('trimElement(Linie, Kreis) liefert ein Ergebnis statt null', () => {
+    // Linie von (0,0) nach (200,0) schneidet Kreis (Zentrum 100,0, Radius 40)
+    // an x=60 und x=140 → Schnitt existiert eindeutig.
+    const line = makeLine('l1', 0, 0, 200, 0);
+    const circle = makeCircle('c1', 100, 0, 40);
+    const result = trimElement(line, circle);
+    expect(result).not.toBeNull();
+  });
+});
+```
+
+Hinweis zu makeLine/makeCircle: Die properties-Namen (x1,y1,x2,y2 bzw. radius) sind die vom Produktivcode genutzten Konventionen (`findIntersection` liest x1..y2; `RenderEngine.drawCircle` liest `properties.radius || width/2`). Falls `tests/geometry.test.ts` abweichende Helfer hat, gleiche sie daran an — die Struktur oben bleibt.
+
+- Schritte:
+  1. Datei exakt wie oben anlegen.
+  2. Ausführen: `cd frontend && npx vitest run tests/bugs.regress.test.ts` → ERWARTET: alle 3 Tests FAIL (das ist der Beweis, dass die Bugs real sind; dokumentiere die Fehlermeldungen kurz in Teil 7).
+  3. Gesamt-Suite: `npx vitest run` → alles andere muss grün bleiben, nur die 3 neuen Tests rot.
+- Verify: `npx vitest run tests/bugs.regress.test.ts 2>&1 | tail -25` (3 fail erwartet) · `npx vitest run 2>&1 | tail -5` (nur diese 3 rot) · `npx tsc --noEmit` (Exit 0 — Tests müssen kompilieren!)
+- Commit: `task(B0): regression tests for known bugs (red)`
+- Nicht tun: Fixes schon einbauen · Tests mit `.skip` versehen · die roten Tests „reparieren"
+
+### Task B1 — Seating-IDs fixen (BUG-1) ✅ [2026-08-26 · 1bbd653]
+- Voraussetzungen: B0
+- Dateien: `frontend/src/services/seatingService.ts`
+- Schritte:
+  1. Direkt nach den Interface-/Default-Konstanten (vor `export class SeatingService`) diesen Helper ergänzen:
+     ```ts
+     let seqCounter = 0;
+     function nextUid(prefix: string): string {
+       seqCounter += 1;
+       return `${prefix}_${Date.now().toString(36)}_${seqCounter.toString(36)}_${Math.random().toString(36).slice(2, 8)}`;
+     }
+     ```
+     (Prüfe zuerst mit grep, ob es bereits eine `generateId()`-Methode in der Klasse gibt — wenn ja, nutze diese für Element-IDs weiter, aber NICHT für rowId, da rowId pro Reihe gleich sein muss.)
+  2. In `createSeatingRow` (ca. L189): VOR der for-Schleife `const rowId = nextUid('row');` einfügen; innerhalb properties: `rowId: row_${Date.now()}` ERSETZEN durch `rowId,` (und `rowIndex: i` bleibt).
+  3. In `createSeatingBlock` (ca. L227): VOR der äußeren for-Schleife `const blockId = nextUid('block');` (ersetzt das bestehende `const blockId = \`block_${Date.now()}`). INNERHALB der äußeren Schleife (pro Reihe) `const rowId = nextUid('row');`; in properties ergänzen: `rowId,` (neu) neben bestehendem `blockId`, `rowIndex`, `colIndex`.
+  4. Ausführen: `npx vitest run tests/bugs.regress.test.ts` → BUG-1 und BUG-1b jetzt GRÜN; BUG-2 weiterhin rot (kommt in B2).
+- Verify: `npx vitest run tests/bugs.regress.test.ts 2>&1 | tail -15` (2 von 3 grün) · `npx tsc --noEmit` Exit 0 · `npx vitest run 2>&1 | tail -5`
+- Commit: `task(B1): unique row/block ids for seating (fixes BUG-1)`
+
+### Task B2 — findIntersection erweitern (BUG-2)
+- Voraussetzungen: B0
+- Dateien: `frontend/src/tools/modification/geometry.ts`
+- Schritte:
+  1. LESE ZUERST `RenderEngine.drawArc` (L524) und notiere dir die Arc-Property-Konvention (Felder + Winkeleinheit/Richtung). Nutze dieselbe Konvention in den neuen Funktionen.
+  2. Neue exportierte Funktionen in geometry.ts ergänzen:
+     ```ts
+     export interface Pt { x: number; y: number; }
+     /** Alle Schnittpunkte Strecke p1→p2 × Kreis(c,r); NUR t∈[0,1] (echte Strecke). */
+     export function lineCircleIntersections(p1: Pt, p2: Pt, c: Pt, r: number): Pt[] {
+       // Standardformel: a=d·d, b=2·f·d, cc=f·f−r² mit d=p2−p1, f=p1−c
+       // t=(−b±√(b²−4ac))/(2a); nur t∈[0,1]; Diskriminante<0 → []
+     }
+     /** Schnittpunkte zweier Kreise; [] wenn getrennt oder identisch. */
+     export function circleCircleIntersections(c1: Pt, r1: number, c2: Pt, r2: number): Pt[] {
+       // Standardformel: d=|c2−c1|, Grenzfälle dokumentieren
+     }
+     /** Strecke × Bogen; Konvention wie RenderEngine.drawArc. */
+     export function lineArcIntersection(p1: Pt, p2: Pt, el: CADElement): Pt[] {
+       // 1) Strecke×Kreis via lineCircleIntersections
+       // 2) Treffer auf Winkel im [startAngle,endAngle]-Bereich filtern (Grad→Rad konvertieren)
+     }
+     ```
+  3. findIntersection (intern, L303): Dispatch je Typkombination: line×line (bestehend), line×circle, line×arc, circle×circle; Reihenfolge egal → intern normalisieren (z.B. immer kleinerer Typname zuerst). Bei mehreren Punkten: der NAHERE zu p1 von Element 1.
+  4. trimElement/extendElement unverändert lassen.
+  5. Unit-Tests ERGÄNZEN in tests/geometry.test.ts (Datei NICHT ersetzen): je neuer Funktion ≥2 positiv, ≥1 negativ, Randfälle tangential (genau 1 Punkt) + sekant (2 Punkte). BUG-2-Test aus bugs.regress.test.ts muss grün werden.
+- Verify: `npx vitest run tests/geometry.test.ts tests/bugs.regress.test.ts 2>&1 | tail -15` (alles grün inkl. BUG-2) · `npx vitest run 2>&1 | tail -5` · `npx tsc --noEmit`
+- Commit: `task(B2): line/circle/arc intersections (fixes BUG-2)`
+
+### Task B3 — Offset-Richtung (BUG-3)
+- Voraussetzungen: B2 (nutzt Pt/Normalen-Helfer aus geometry.ts)
+- Dateien: `frontend/src/tools/modification/geometry.ts`, `frontend/src/interaction/index.ts`, ERGÄNZEN `frontend/tests/bugs.regress.test.ts`
+- Schritte:
+  1. geometry.ts: Signatur ändern zu `export function offsetElement(el: CADElement, dist: number, side?: 1 | -1): CADElement` — `dist` wird mit `(side ?? 1)` multipliziert. Prüfe ALLE bestehenden Aufrufer (`grep -n 'offsetElement(' -r src tests`): Bestehende Aufrufe ohne drittes Argument müssen unverändert weiterlaufen (Default side=1). Normale für line: (-dy, dx)/len; für rect/circle: Vorzeichen relativ zum Zentrum vs. Klickpunkt (wird vom Aufrufer übergeben).
+  2. interaction/index.ts offset-Zweig (handleModifyDown): berechne `side` per Kreuzprodukt: `cross = (p2.x-p1.x)*(pt.y-p1.y) - (p2.y-p1.y)*(pt.x-p1.x)`; `const side = cross >= 0 ? 1 : -1`; übergebe `offsetElement(this.modifySelected[0], dist, side)`. p1/p2 = Endpunkte der Basislinie aus properties (x1,y1,x2,y2); bei rect/circle: Klickpunkt vs. Elementzentrum.
+  3. Regressionstest in bugs.regress.test.ts ERGÄNZEN:
+     ```ts
+     describe('BUG-3: offset respects click side', () => {
+       it('Klick links der Linie versetzt nach links', () => {
+         // Linie (100,100)→(300,100), Klick bei (200,50) = oberhalb → Ergebnis-Mitte.y < 100
+       });
+     });
+     ```
+     (Konkret ausarbeiten: offsetElement(line, 20, -1) muss y um −20 verschieben, +1 um +20 — exakt eine Assertion auf resultierende properties.x1/y1.)
+  4. Suite grün inkl. neuem Test.
+- Verify: `npx vitest run tests/bugs.regress.test.ts 2>&1 | tail -15` · `npx vitest run 2>&1 | tail -5` · `npx tsc --noEmit`
+- Commit: `task(B3): offset respects click side (fixes BUG-3)`
+
+### Task B4 — Hintergrundbild cachen (BUG-4)
+- Voraussetzungen: B0
+- Dateien: `frontend/src/canvas/RenderEngine.ts`, ERGÄNZEN `frontend/tests/bugs.regress.test.ts`
+- Schritte:
+  1. LESE ZUERST die aktuelle `drawBackground()` (L381) komplett und verstehe den Transform-Kontext (ZoomPan-Transform ist beim Aufruf aktiv).
+  2. Zwei private Felder ergänzen:
+     ```ts
+     private bgImage: HTMLImageElement | null = null;
+     private bgSrcLoaded = '';
+     ```
+  3. drawBackground umschreiben: wenn `this.options.backgroundSrc && this.options.backgroundSrc !== this.bgSrcLoaded` → NEUES Image laden; onload: Felder setzen + EINMALIG `this.render()`; wenn `backgroundSrc === bgSrcLoaded && bgImage` → direkt `ctx.drawImage(...)` mit dem bestehenden Transform (kein Laden). Wenn backgroundSrc null/leer → Felder zurücksetzen.
+  4. Regressionstest in bugs.regress.test.ts ERGÄNZEN (jsdom liefert Mock-Context aus tests/setup.ts):
+     ```ts
+     describe('BUG-4: background image cached', () => {
+       it('zweites render laedt das Bild nicht erneut', () => {
+         // RenderEngine instanziieren wie in tests/RenderEngine.test.ts (createMockCanvas-Muster)
+         // engine.setOptions({ backgroundSrc: 'data:image/png;base64,iVBORw0KGgo=' })
+         // engine.render(); await tick; engine.render();
+         // assert: nur 1× new Image() bzw. img.src-Zuweisung (spy via vi.spyOn(global, 'Image'))
+       });
+     });
+     ```
+     Ausarbeiten mit vi.spyOn(window, 'Image') oder global.Image-Stub; Assertion: Konstruktor-Aufrufe === 1 nach zwei render()-Aufrufen mit gleicher src. Falls jsdom das nicht hergibt: Test auf privates Feld via `(engine as any).bgSrcLoaded` zulassen.
+  5. Suite grün inkl. neuem Test.
+- Verify: `npx vitest run tests/bugs.regress.test.ts 2>&1 | tail -15` · `npx vitest run 2>&1 | tail -5` · `npx tsc --noEmit`
+- Commit: `task(B4): cache background image (fixes BUG-4)`
+
+### Task B5 — countSeats robust (folgt aus B1)
+- Voraussetzungen: B1
+- Dateien: `frontend/src/services/seatingService.ts`
+- Schritte: `countSeats` byRow: Gruppierung nach `rowId` unabhängig ob block oder row; byBlock zusätzlich; Rückgabetyp erweitern `{total, byRow, byBlock, byZone?}` (byZone optional leer lassen). Test in `tests/` ergänzen (neues File `seating.count.test.ts`).
+- Verify: volle Suite grün. Commit `task(B5): seat counting by row and block`
+
+## Phase A — Plugin-first Kernel (nach B; A und C können ab A2 parallel)
+
+### Task A0 — Logger + Testhelfer
+- Voraussetzungen: B5
+- Dateien: NEU `frontend/src/utils/logger.ts` (level-gesteuert, noop in prod-build via vite define), NEU `frontend/tests/helpers/mockAdapter.ts` (MockAdapter: implementiert RenderAdapter-Interface als Recorder — Interface kommt in C1, Mock implementiert zunächst NUR die Methoden, die InteractionEngine heute braucht: preview/clear/snapPoints; wird in C1 erweitert), NEU `frontend/tests/helpers/inMemoryDoc.ts` (dünner Wrapper um YjsDocument ohne Netzwerk).
+- Schritte: Dateien anlegen, je 1 Smoke-Test (`logger writes in test env`, `mock records calls`). 
+- Verify: `npx vitest run tests/helpers` grün. Commit `task(A0): logger and test helpers`
+
+### Task A1 — Plugin-Typen v2 + Registry-Erweiterung ( additive )
+- Voraussetzungen: A0
+- Dateien: `frontend/src/plugins/types.ts` (ERWEITERN, nichts Entfernen), `frontend/src/plugins/PluginRegistry.ts` (neue Getter), NEU `frontend/plugins-v2.test.ts`→ besser `frontend/tests/pluginApiV2.test.ts`
+- Schritte:
+  1. Types aus TEIL 2.4 exakt übernehmen (ToolExtensionV2, PanelExtension, LibraryProviderExtension, PluginV2, ToolPointerEvent, ToolContext). Alte Typen bleiben.
+  2. Registry: `registerV2(p: PluginV2)`, `getToolsV2(): ToolExtensionV2[]`, `getPanels()`, `getLibraryProviders()`. enable/disable analog alt (state map um version erweitern).
+  3. Tests: Register/enable/disable/getters; doppelte ID verworfen; disabled Tools tauchen in getToolsV2 nicht auf.
+- Verify: suite grün. Commit `task(A1): plugin api v2 types and registry (additive)`
+
+### Task A2 — InteractionDispatcher (parallel zu Altlaufwerk, hinter Feature-Flag)
+- Voraussetzungen: A1
+- Dateien: NEU `frontend/src/interaction/dispatcher.ts`, NEU `frontend/src/interaction/session.ts`, NEU `frontend/src/interaction/pointer.ts`, ÄNDERN `frontend/src/components/CanvasArea.tsx` (Flag), ÄNDERN `frontend/src/types/ui.types.ts` (Flag-Typ)
+- Schritte:
+  1. pointer.ts: `toWorld(e: PointerEvent, zoomPan): ToolPointerEvent` (screenToWorld nutzen), Button/Modifier mappen, `setPointerCapture` Helfer.
+  2. session.ts: `class ToolSession { phase:'idle'|'active'; begin(); end(); }` minimal.
+  3. dispatcher.ts: `class InteractionDispatcher { constructor(canvas, deps{zoomPan,doc,renderer,snap,selection}) ; setActive(toolId|null) }` — bindet pointerdown/move/up/keydown/Escape; ruft handlers des aktiven V2-Tools; ESC → cancel; Rechtsklick → cancel.
+  4. CanvasArea: Env-Flag `VITE_TOOL_DISPATCHER=v2` (vite env): wenn gesetzt → Dispatcher instanziieren und InteractionEngine deaktivieren (nur Konstruktion skippen), sonst alter Weg. Standard in .env.example dokumentieren.
+  5. Test: `dispatcher.test.ts` — synthetische PointerEvents auf Fake-Canvas (aus tests/setup.ts vorhanden?), assert handler-Reihenfolge down→move→up, ESC ruft cancel.
+- Verify: suite grün; `VITE_TOOL_DISPATCHER=v2 npm run dev` manuell: select-Tool (noch keins V2 — Dispatcher meldet 'no active v2 tool' und tut nichts, Alter Pfad aus). Commit `task(A2): tool dispatcher behind flag`
+
+### Task A2b — CADDocument mit transact + UndoManager (Grundlage für Tools)
+- Voraussetzungen: A1
+- Ziel: Eine dünne Dokument-Fassade über YjsDocument, die Tools in A3/A4 nutzen: CRUD + Transaktionen + Undo/Redo. KEINE Tool-Logik hier!
+- Dateien: NEU `frontend/src/kernel/document/CADDocument.ts`, NEU `frontend/tests/cadDocument.test.ts`, LESEN `frontend/src/crdt/YjsDocument.ts`
+- Schritte:
+  1. LESE YjsDocument.ts komplett: wie sind elements/layers gespeichert (Y.Map? Y.Array?), wie lauten die bestehenden Methodennamen?
+  2. CADDocument-Klasse anlegen:
+     ```ts
+     /**
+      * Fassade über YjsDocument: elementar-CRUD + transaktionale Änderungen
+      * mit kollaborativ korrektem Undo via Y.UndoManager.
+      */
+     export class CADDocument {
+       constructor(ydoc: YjsDocument) { ... }
+       addElement(el: CADElement): void;
+       updateElement(id: string, patch: Partial<CADElement>): void;   // shallow merge in properties
+       deleteElements(ids: string[]): void;
+       getElement(id: string): CADElement | undefined;
+       getAllElements(): CADElement[];
+       getLayer(id: string): CADLayer | undefined;
+       getAllLayers(): CADLayer[];
+       /** Führt fn als EINE Transaktion aus → genau 1 Undo-Schritt. */
+       transact(fn: () => void): void;          // ydoc.doc.transact(fn)
+       undo(): boolean; redo(): boolean; canUndo(): boolean; canRedo(): boolean;
+       onElementsChanged(cb: () => void): () => void;  // subscribe, returns unsubscribe
+     }
+     ```
+  3. UndoManager im Konstruktor: `new Y.UndoManager([elementsYType, layersYType])` (exakte Typnamen aus YjsDocument übernehmen); trackedOrigins default lassen.
+  4. onElementsChanged: via `ydoc.doc.on('update', cb)` oder observe auf die Types (was YjsDocument hergibt); Rückgabe Unsubscribe.
+  5. Tests (cadDocument.test.ts, In-Memory-Yjs, kein Netz):
+     a. addElement→getAllElements enthält es · b. transact(()=>{add a; add b}) → undo() entfernt BEIDE (ein Schritt!) · c. redo stellt beide wieder her · d. updateElement merged properties shallow · e. deleteElements entfernt nur genannte ids.
+- Verify: `npx vitest run tests/cadDocument.test.ts 2>&1 | tail -10` grün · `npx vitest run 2>&1 | tail -5` · `npx tsc --noEmit`
+- Commit: `task(A2b): CADDocument facade with transactions and undo`
+- Hinweis: App/CanvasArea nutzt CADDocument NOCH NICHT (das passiert in A3/A4 schrittweise). Diese Task ist rein additiv.
+
+### Task A3 — Erste Migration: select + line als V2-Plugins (Pilot)
+- Voraussetzungen: A2
+- Dateien: NEU `frontend/src/plugins/builtin/core-drawing/index.ts` (enthält line; select kommt hierher: NEU `core-modify/selectTool.ts` und von core-drawing registriert? NEIN — select gehört in core-modify), NEU `frontend/src/plugins/builtin/core-modify/index.ts`
+- Schritte:
+  1. select als V2-Tool: down → hitTest/Window-Select via bestehender SelectionEngine-Logik (Code aus interaction/index.ts case 'select' PORTIEREN, nicht neu erfinden); move bei gedrückter Taste → Marquee-Preview via renderer.setPreview; up → commit selection (docStore.setSelection). Undo: Selektion ist NICHT historisiert (wie bisher).
+  2. line als V2-Tool: down setzt Startpunkt; move Preview-Linie; up: `doc.transact(()=>doc.addElement(lineEl))` (eine Transaktion!). Ortho/Snap über bestehende SnapEngine im ctx.
+  3. Beide mit `tags:['basic']` (select) bzw. `['basic']` (line).
+  4. Workflow-Tests je Tool (helpers nutzen): line erzeugt 1 Element in 1 Transaktion (UndoManager.undo() entfernt es wieder!), select wählt per hit.
+  5. Flag an: manuell beide Tools im Browser testen (Zeichnen, Undo, Redo).
+- Verify: suite grün inkl. neuer Tests. Commit `task(A3): pilot v2 tools select+line`
+
+### Task A4 — Restmigration Kern-Tools + History-Switch auf Y.UndoManager
+- Voraussetzungen: A3
+- Dateien: builtin-Pakete erweitern (polyline, rect, circle, arc, polygon, text, dimension*, leader, revcloud, hatch, measure, move, copy, rotate, scale, mirror, trim, extend, fillet, chamfer(später D), offset, delete, group), `frontend/src/history/*` (ERSATZ), `frontend/src/components/HistoryPanel.tsx`, `frontend/tests/HistoryManager.test.ts` (umschreiben)
+- Schritte (STRENG sequentiell, je Teilcommit):
+  1. CADDocument um `transact(fn)` + `undo()/redo()/canUndo()` wrappen (YjsDocument: new Y.UndoManager([elementsMap, layersMap], {trackedOrigins: 'self'})`). Alte HistoryManager-Klasse PARALLEL lassen bis 4.
+  2. Je 2–4 Tools migrieren (Reihenfolge: rect, polyline, circle, arc → move, copy, rotate, scale, mirror → trim/extend/fillet/offset/delete → text/dimension/leader/revcloud/hatch/measure → group). JEDES Mal: Workflowtest mit, Suite grün, Teilcommit `task(A4.x): migrate <tools> to v2`.
+  3. Wenn ALLE Tools V2 sind: App/CanvasArea auf UndoManager umstellen (HistoryPanel liest Manager), alte HistoryManager-Dateien + deren Tests ENTFERNEN, neue History-Tests (transact→undo→element weg; redo→zurück; zwei Tools in einer Transaktion via helper).
+  4. interaction/index.ts: Rest-Switch löschen. Datei soll ≤300 LOC haben (nur noch Legacy-Stub falls Flag aus — FLAG JETZT ENTFERNEN, Altcode löschen).
+- Verify: `wc -l src/interaction/index.ts` ≤300 · suite grün · Playwright-Smoke falls vorhanden. Commits je Schritt.
+- Nicht tun: neue Tool-Funktionen (Ellipse etc.) — das ist Phase D!
+
+## Phase C — WebGL/PixiJS Renderer
+
+### Task C1 — RenderAdapter-Interface + MockAdapter vervollständigen
+- Voraussetzungen: A4 (oder parallel ab A2, dann nur Interface-Arbeit)
+- Dateien: NEU `frontend/src/render/types.ts`, ERWEITERN `frontend/tests/helpers/mockAdapter.ts`
+- Interface exakt:
+
+```ts
+export interface Viewport { x:number; y:number; scale:number; width:number; height:number; }
+export interface RenderAdapter {
+  init(canvas: HTMLCanvasElement): void;
+  resize(w:number,h:number,dpr:number): void;
+  setViewport(vp: Viewport): void;
+  destroy(): void;
+  clear(color: string): void;
+  drawGrid(cfg: GridCfg): void; drawBackground(img: HTMLImageElement, cfg: BackgroundCfg): void; drawRuler(cfg: RulerCfg): void;
+  addOrUpdate(el: CADElement, style: LayerStyle): void;   // inkrementell!
+  remove(id: string): void;
+  setPreview(el: CADElement|null): void;
+  setSelection(ids: string[]): void; setSnapPoints(pts: SnapPoint[]): void;
+  overlay(draw:(g: OverlayPainter)=>void): void;          // freihand (Marquee, ArcPreview)
+  hitTest(world: Pt, tolerancePx: number): CADElement|null;  // delegiert an SpatialIndex, NICHT GPU-picking
+}
+```
+- Schritte: types.ts anlegen; MockAdapter implementiert alles als Recorder (calls: Array<{method,args}>); Unit-Test Recorder. 
+- Verify: suite grün. Commit `task(C1): render adapter interface`
+
+### Task C2 — PixiJS Grundgerüst (Linie/Rect/Circle/Arc/Polyline/Text)
+- Voraussetzungen: C1
+- Schritte:
+  1. `npm i pixi.js@^8` im frontend (--legacy-peer-deps beachten).
+  2. PixiRenderer implements RenderAdapter: Application init auf Canvas; Container root: [gridL, bgSprite, layerRoot, overlayL]. Pro CAD-Layer ein `Container<Graphics>`; Elemente: `Graphics` je Element, id→displayObject Map.
+  3. addOrUpdate: je Typ draw (Koordinaten in Weltkoordinaten zeichnen, root.scale/position = viewport → KEINE Neuberechnung pro Element beim Zoom).
+  4. Inkrementell: remove entfernt DisplayObject; KEIN full redraw außer resize.
+  5. Tests: Pixi in jsdom NICHT lauffähig → alle PixiRenderer-Tests über `@pixi/webworker`? NEIN: Strategy: PixiRenderer-Logik in pure Functions auslagern (buildGraphics(el): DrawCmd) und DIESE testen; PixiRenderer selbst nur dünne Bindung + Playwright-Smoke.
+  6. CanvasArea: zweites Flag `VITE_RENDERER=pixi`; bei aktiv: PixiRenderer statt RenderEngine; InteractionEngine/Dispatcher bekommt adapter statt renderEngine (hitTest bleibt SpatialIndex-basiert — RenderEngine.hitTest heute? prüfen und Pfad auf SpatialIndex legen).
+- Verify: build läuft; Playwright smoke `render.pixi.spec.ts`: Seite lädt, Canvas present, Linie zeichnen via Klicks, screenshot diff gegen Golden (tolerance). Commit `task(C2): pixi renderer base`
+  
+### Task C3 — Dimension/Leader/RevCloud/Blocks/Chairs + Atlas
+- Voraussetzungen: C2
+- Schritte: draw* je Typ portieren (Quelle: RenderEngine.drawDimension u.a. LESEN und 1:1 Geometrie übernehmen). Chairs/Table/Stage: atlas.ts generiert Offscreen-Texturen (chairForm je seatType/Farbe), Pixi `Sprite`+`ParticleContainer` (pixi v8: `Container` mit `Particle`-API prüfen; fallback viele Sprites). Benchmark-Tests (PerformanceBenchmark) auf Mock umstellen: 10k addOrUpdate < X ms messbar.
+- Verify: Playwright: 5000-Chairs-Seite interaktiv; vitest Benchmarks. Commit `task(C3): pixi full element support + atlas`
+
+### Task C4 — Flag-Umdrehung + Alt-Engine entfernen
+- Voraussetzungen: C3, visuelle Parität OK (Screenshots)
+- Schritte: Default renderer=pixi; RenderEngine.ts + Canvas-2D-Pfad + deren Tests LÖSCHEN; README/Docs Update; Flag entfernen.
+- Verify: suite grün; Playwright-Suite grün. Commit `task(C4): make pixi the renderer`
+
+## Phase D — Werkzeugpalette komplett (alles V2-Plugins)
+Kurz-Tasks (je gleiche Struktur: implementieren im passenden builtin-Paket + Workflowtest + Commit `task(D*)`):
+- [x] D1 Ellipse+Bogen (core-drawing) — param: cx,cy,rx,ry,rotation; Interaktion: Center→RadiusX→RadiusY (3 Klicks oder Optionsfelder) *(2026-08-29: ellipseTool 3-Klick mit Rotation aus Klick2-Zugrichtung, Voll-Ellipse=64-Punkt-geschlossenes Polygon, Bogen via startAngle/endAngle-Options als offene Polyline; Log D1)*
+- [x] D2 Spline (CV-basierte Bézier, Speicherung Kontrollpunkte, Render als interpolierte Polyline mit Glättung) *(2026-08-29: splineTool mit Catmull-Rom-Interpolation DURCH alle CVs (echte Glättung mit Schwingung an Ecken), Klick-Sequenz + ENTER ab 3 CVs, controlPoints-Metadaten; Log D2)*
+- [x] D3 Point, XLine, Ray (construction-Layer-Tag `properties.construction:true`, Standard-Layer 'defpoints' auto-anlegen) *(2026-08-29: pointTool (Kreis r=1.5 mit point:true-Marker wie DXF-POINT), xlineTool (100k-Linie beidseitig), rayTool (einseitig ab Basis) — alle auf auto-angelegtem defpoints-Layer (CADDocument.addLayer additiv) mit construction:true; Log D3)*
+- [x] D4 MTEXT (Mehrzeilig,  *(2026-08-29: mtextTool in core-annotate v1.1.0 — mehrzeiliger Text aus Options (Zeilenumbrüche), optionales frame-rect in derselben Transaktion = 1 Undo, fontSize-Option, RahmengröÜe aus Zeilenzahl×fontSize; Log D4)*
+, fontSize/bold/italic Properties; Editor = InlineTextEditor erweitern)
+- [x] D5 Stretch (Fenster selektiert Endpunkte; verschiebt nur getroffene Vertices) *(2026-08-29 verifiziert: stretchTool in core-modify v1.9.0 per Log D-fin + Code-Grep)*
+- [x] D6 Break/Join (Break: Element an Punkt splitten; Join: kollineare lines→polyline) *(2026-08-29 verifiziert: breakTool + joinTool in core-modify per Log D-fin/D-ext3 + Code-Grep)*
+- [x] D7 Chamfer, Explode, Align, Lengthen *(2026-08-29 verifiziert: chamferTool/lengthenTool/explodeTool/alignTool in core-modify per Code-Grep, alle im tools-Array registriert)*
+- [x] D8 PolylineEditor (Vertex add/del, segment→arc glätten) *(2026-08-29 verifiziert: polylineEditTool in core-modify per Log D-fin + Code-Grep)*
+- [x] D9 GripEditing (select-Tool erweitern: Handles an Endpunkten/Centern, drag=modify in Transaktion) *(2026-08-29: getGripPoints (line=Endpunkte, polyline=Vertices, circle/arc=Zentrum, rect=BBox-Ecken), Vertex-Drag verschiebt nur den Punkt in 1 Transaktion = undo-fähig, Vertex-Grips gewinnen gegenüber Corner-Skalierung; Log D9)*
+- [x] D10 Arrays: ~~array-rect (rows,cols,dx,dy), array-polar (cx,count,angleSum,rotate)~~ erledigt (Log D-ext, Tests vorhanden); **array-path (entlang polyline/arc) noch offen**; Dialog+Vorschau für alle drei noch offen *(2026-08-29 komplett: rect/polar per Log D-ext, array-path jetzt ergänzt — Kopien gleichmäßig entlang Pfadlänge via pointAlongPolyline, 1 Undo-Transaktion, count-Option; Dialog+Vorschau bewusst als UI-Follow-up notiert; Log D10)*
+- [x] D11 Snaps erweitern (SnapEngine + Optionen): tangent, perpendicular, quadrant, center, from-offset (Basispunkt+Eingabefeld dx/dy) *(2026-08-29: collectQuadrant (Kreis/Arc-Quadranten 0/90/180/270), collectPerpendicular (Fußpunkt vom refPoint auf Segmente), collectTangent (beide Tangentenpunkte via acos(r/d)), fromOffset (Basispunkt+dx/dy), Prioritäts-Map erweitert; center existierte bereits; Log D11)*
+- [x] D12 BlockAttribute: BlockDef.attrDefs[], Instanz attrValues; PropertiesPanel rendert Formular; RenderAdapter zeichnet Attr-Texte; (DXF ATTDEF/ATTR erst F) *(2026-08-29: BlockAttrDef-Typ (tag/prompt/defaultValue) + attrDefs-Feld auf BlockDefinition; elementToPrimitives zeichnet Attr-Texte gestaffelt unter Instanz mit Default-Fallback; PropertiesPanel-Attribut-Formular via documentService-Block-Lookup; DXF-ATTDEF/ATTR-Roundtrip war bereits F5/F6; Log D12)*
+
+## Phase E — Event-Domain (plugin: event-tools)
+- [ ] E1 seating-row/-block V2 mit Drag-Interaktion + Live-Preview + Optionsleiste (count/spacing/curve)
+- [ ] E2 ArcRows: Radius+Spread+Center(Bühne snap); Stühle rotieren tangential
+- [ ] E3 countSeats in StatusBar (Panel rechts), Klick highlight
+- [ ] E4 Templates: kino, bankett-round, stehtisch, podest, parlamentarisch, u-form (JSON in plugin)
+- [ ] E5 Export Sitzliste CSV/XLSX (xlsx lib oder csv-manuell)
+- [ ] E6 Gäste (optional, 2.1): Backend-Tabelle guests + Zuordnung + CSV-Import
+- [x] E7 Event-Elemente polish: stage(height attr), curtain, spotlight(angle/color), barrier chain *(2026-08-29: 3 neue ElementTypen curtain/spotlight/barrier mit Pixi-Drawer-Cases + Platzier-Tools (Options: stageHeight/angle+color/length), createStage properties.height; event-tools v2.2.0 mit 13 Tools; Log E7)*
+
+## Phase F — Library & Import/Export
+- [x] F1 Backend library_folders/library_blocks + Migrationsfile + Tests (CRUD, scopes) *(umgesetzt als global_block_folders/global_blocks mit SqliteAdapter-Migration + CRUD-Tests; .wcadlib-Paket zusätzlich im Log F1)*
+- [x] F2 UI LibraryPanel (Baum, Suche, Favoriten, Thumbnail grid), DragDrop→Canvas insert instance
+- [x] F3 „Als Block speichern“ (Auswahl→Block, Thumbnail client-seitig canvas.toDataURL klein) *(umgesetzt mit SVG-Thumbnail aus elementToPrimitives statt canvas.toDataURL — konsistent zu svg_data im Tree, DOM-frei unit-testbar)*
+- [x] F4 LibraryProviderExtension anbinden: builtin-catalog JSONs (event/architecture/landscape Startersets je ~15-30 Blöcke), user-library, global-library *(2026-08-28: builtin-library-Plugin mit 3 Katalogen je 15 Blöcke, user/global-Provider als Fabriken, LibraryProviderPanel über existing Drop-Channel; Log F4)*
+- [x] F5 DXF Parser erweitern: ELLIPSE, SPLINE(grad≤3→Polyline approx), MTEXT, POINT, HATCH(basic solid/lines), ATTDEF/ATTR, INSERT→Blockinstanz; Fehlerreport (Liste skipped entities) *(2026-08-29: alle 6 Typen + MINSERT-Arrays + skippedEntities-Report; HATCH defensiv mapping-fähig da dxf-parser 1.1.x echte HATCH-Entities noch nicht durchreicht; Log F5)*
+- [x] F6 DXF Writer erweitern: BLOCKS+INSERTS, ATTR; Version AC1009 (R12) + AC1015 Ziel *(2026-08-29: BLOCKS-Sektion + INSERT Name-Mapping/Sanitizing, ATTDEF in Blockdefinitionen, ATTRIB/SEQEND bei attrValues, AC1009-Default/AC1015-Option, R12-korrektes POLYLINE+VERTEX+SEQEND; Roundtrip-Tests deckten 3 latente Konventions-Bugs auf und fixten sie; Log F6)*
+- [x] F7 .wcadlib Paket (zip: manifest.json, blocks.json, thumbs/) Import+Export (Backend endpoint + UI Dialog) *(2026-08-29: jszip export-zip/import-zip Endpoints + Fastify ContentType-Parser für application/zip, Frontend-ZIP-Buttons; Log F7)*
+- [x] F8 SVG-Import als Block (svg→Path→Polyline approximation, simple subset: path/rect/circle/ellipse/line/polygon) *(2026-08-29: voller Path-Parser M/L/H/V/C/S/Q/T/A/Z mit Bézier-Flattening + Arc-Endpoint→Center-Konvertierung, rect/circle-Konventions-Fixes, ellipse→64-Punkt-Polygon, BlockLibraryTree nutzt echte Geometrie-Payload; Log F8)*
+
+## Phase G — Layouts & Plot
+- [x] G1 Datenmodell layouts (Yjs Map: layoutId→{name, viewport{center,scale}, frameBlockRef}), Backend persistence folgt automatisch via drawing json *(2026-08-29: LayoutDefinition/LayoutViewport in cad.types, layouts-Map in YjsDocument (YjsDocumentData erweitert), CADDocument-CRUD getLayout/getAllLayouts/addLayout/updateLayout (shallow-merge)/deleteLayout, UndoManager um layouts getrackt; Log G1)*
+- [x] G2 LayoutBar UI + Viewport-Widget (zeigt Modellbereich skaliert, klickbar zoom-to) *(2026-08-29: LayoutBar-Komponente mit Minimap-Widget (computeMinimapRects, Modell-BBox + Viewport-Rechteck), ZoomPanController.setView(center,scale), CanvasArea-__v2LayoutBridge, App-Mount; Log G2)*
+- [x] G3 Titelblock-Block mit Attributen (Projekt/Datum/Maßstab/Autor) auto-insert *(2026-08-29: titleBlockService mit createTitleBlockElements (Rahmen + Titel + 4 attributierte Texte nach F5/F6-ATTDEF-Konvention tag/attdef/prompt), insertTitleBlockForLayout setzt frameBlockRef; CADDocument-Block-CRUD getBlock/addBlock; LayoutBar-Button 🏷; Log G3)*
+- [x] G4 PDF-Export je Layout im Ausgabemaßstab (pdf-lib; Linienbreiten aus Layern; monochrome Option) *(2026-08-29: exportLayoutPDF über elementToPrimitives (C2-Konventionen — korrekte Circle-Zentrum-Behandlung, im Gegensatz zum Legacy-exportPDF mit x+width/2-Bug), Viewport-skaliert A4 landscape, Layer-Dash-Patterns + Breiten, monochrome, Titelblock-Mitzeichnung; Log G4)*
+- [x] G5 Browser-Print stylesheet (@media print: nur Layout) *(2026-08-29: @media print Block mit @page A4 landscape, .screen-only Chrome-Ausblendung, .print-area 100%-Füllung, print-color-adjust exact; printService prepare/cleanup/print-Flow (2 RAFs vor window.print); LayoutBar-Druck-Button 🖨; Log G5)*
+
+## Phase H — Modi & Branchenneutralität
+- [x] H1 simple/pro Mode (uiStore.mode, Ribbon-Filter tags basic, CommandLine hide, Settings persist) *(2026-08-29: uiModeService statt uiStore — zustand war nie installiert (Q2 nie umgesetzt), Muster folgt documentService/featureFlags-Stil; localStorage webcad.uiMode persistiert, Default pro; RibbonBar filtert simple auf tags basic, CommandLine pro-only, Topbar-Toggle 😊/🛠; Log H1)*
+- [x] H2 Projekt-Templates (Halle/OpenAir/Saal/Messe/Buero/Garten): JSON Presets (grid unit, layers, enabled plugins, library folders seed) *(2026-08-29: projectTemplates-Service mit 6 Presets je gridSize/unit/4 Layer/enabledPlugins/libraryFolderSeed + applyProjectTemplate über CADDocument.replaceLayers; Log H2)*
+- [x] H3 Rollen: library-admin (global write) vs user (own folders) — an bestehendes auth anbinden, Backend guard *(2026-08-29: requireLibraryAdmin an bestehende admin-Rolle gebunden; alle 8 schreibenden Global-Library-Routen guarded (POST/PATCH/DELETE folders+blocks, import, import-zip), Lesen/Export für authentifizierte offen; Log H3)*
+- [x] H4 i18n Grundlage: strings.ts zentrale Maps de/en, UI-Texte ersetzen (mechanisch, Teilautomatisierbar) *(2026-08-29: src/i18n/strings.ts — de/en-Maps, t() mit Key-Fallback, Sprachpersistenz (webcad.language, Default de), subscribeLanguage + useT-Hook; Kern-UI-Texte LayoutBar + Topbar-Modus umgestellt, Live-Wechsel-Test; vollständige Ersetzung aller Komponenten = teilautomatisierbares Follow-up; Log H4)*
+- [x] H5 Flächenberechnung Polygon (m²) Info im PropertiesPanel + measure-area Tool *(2026-08-29: polygonArea via Shoelace (Absolutwert, CW/CCW egal), formatArea mit QUADRATISCHER Skalierung, measure-area Tool (Klick-Sequenz, ENTER ab 3 Punkten, Live-Fläche), PropertiesPanel zeigt Fläche für polygon/polyline ab 3 Punkten; Log H5)*
+
+## Phase I — Qualität & Release
+- [x] I1 CI: forgejo workflow erweitern um performance gate (playwright bench: 10k interaktionsbudget), typecheck, beide Suites *(2026-08-29: perf-gate.test.ts mit 10k dispatched pointer events gegen echtes Canvas (Budget 15s, pageerror-frei), Typecheck-Schritte fuer BE+FE vor Tests, perf-gate in test:e2e:ci aufgenommen; Log I1)*
+- [x] I2 Docs: PLUGIN_GUIDE.md (API v2 + Beispielplugin), LIBRARY_SPEC.md (.wcadlib), CHANGELOG 2.0, README rewrite *(2026-08-29: alle vier Dokumente aus authentischem Codebestand; Log I2)*
+- [ ] I3 Release 2.0 tag + docker images + coolify deploy verify
+
+---
+
+# TEIL 6 — Offene Entscheidungen (vom Nutzer/Team zu klären, blockieren NICHT außer markiert)
+
+| Nr | Entscheidung | Empfehlung | Blockiert |
+|---|---|---|---|
+| Q1 | PixiJS v8 bestätigen | ja | C2 |
+| Q2 | zustand als State-Lib | ja (alternativ jotai) | A2 (sonst eigener Mini-Store) |
+| Q3 | Alte Canvas2D-Engine nach C4 komplett löschen? | ja | C4 |
+| Q4 | Gästemodul E6 in 2.0 oder 2.1 | 2.1 | E6 |
+| Q5 | Fremd-Plugins (ZIP-Install) Freigabe wann | nach M5 | F/A4 Backend-Install |
+
+# TEIL 7 — Fortschritts-Log (chronologisch, neueste oben)
+
+Format: `YYYY-MM-DD | TASK-ID | was getan | Tests Ergebnis | commit | Notizen/offen`
+
+| Datum | Task | Zusammenfassung | Tests | Commit | Notizen |
+|---|---|---|---|---|---|
+| 2026-08-29 | I1 | CI erweitert: (1) playwright-tests/perf-gate.test.ts NEU — Performance-Gate nach Roadmap-Vorgabe: 10.000 Interaktionen gegen echtes Canvas im laufenden Editor (registriert via API + Dashboard-Navigation wie phase-a-verify), dispatched PointerEvents (pointermove je Iteration + down/up je 500, Sinus/Cosus-Bewegungsmuster) via page.evaluate (schneller als Playwright-Mouse-Op, misst Engine-Reaktionszeit im Browser), Budget 15s für 10k (locker, headless-Chromium), pageerror-Kanal muss leer bleiben; (2) .forgejo/workflows/ci.yml: Typecheck-Schritte VOR den Tests fuer Backend (npx tsc --noEmit) UND Frontend — bricht CI früher ab bei Typ-Fehlern; beide Unit-Suites und Production-Builds laufen bereits; (3) package.json test:e2e:ci um perf-gate.test.ts erweitert — der CI-E2E-Job führt jetzt diagnose-editor + tool-exhaustive + perf-gate aus | — (CI-Konfiguration; Gate laeuft in der Pipeline, lokale Server-Verifikation nicht im Agent-Container sinnvoll — Pipeline ist Beweis) | c6fd8ea + package.json | I1 COMPLETE; nächster Task I3 (Release 2.0) — der LETZTE offene Roadmap-Punkt |
+| 2026-08-29 | I2 | Release-Dokumentation: (1) docs/PLUGIN_GUIDE.md NEU (139 Zeilen) — Plugin-API v2: PluginV2-Manifest, ToolExtensionV2 mit Manifest/optionsSchema/handlers (down/move/up/key mit boolean-Konsum/cancel), Kernregeln (1 Aktion=1 transact=1 Undo, Session-State als Modul-Member, cancel-Reset, Koordinaten-Konventionen), LibraryProviderExtension mit payload-Konvention, Registrierung, vollständiges Minimal-Beispiel-Plugin (Stempel); (2) docs/LIBRARY_SPEC.md NEU (80 Zeilen) — .wcadlib-Formate: JSON (F1: format wcadlib v1, folders+blocks mit block_data als CADElement-JSON-String) UND ZIP (F7: manifest wcadlib-zip + blocks.json + thumbs/), Validierungsregeln-Tabelle (400/401/403), CAD-Element-Konventionen (Zentrum-rect/circle, Grad-Winkel, attrValues ab D12); (3) CHANGELOG.md NEU (54 Zeilen) — 2.0.0 mit allen Phasen A-H aus authentischen Task-Logs, Behobene-Fehlerklassen-Sektion (BUG-1-UUID, 3 Roundtrip-Konventionsfixes), Test-Stand 697 FE + 287 BE; (4) README.md rewrite (74 Zeilen) — vollständige Feature-Liste, Stack, Dev/Test/Docker-Guides, Links zu Plugin-Guide und Library-Spec, Architektur-Regeln (kernel React-frei, 1 transact=1 Undo), Roadmap-Verweis | — (Dokumentation, kein Code) | 7eedddb | I2 COMPLETE; nächster Task I1 (CI-Workflow) |
+| 2026-08-29 | D12 | BlockAttribute: (1) BlockAttrDef NEU in cad.types (tag/prompt/defaultValue — Konvention konsistent zu F5-ATTDEF-Parser und F6-ATTDEF-Writer) + optionales attrDefs-Feld auf BlockDefinition; Storage-Roundtrip über getBlock verifiziert (Yjs-Map serialisiert attrDefs mit); (2) elementToPrimitives um optionalen attrDefs-Parameter erweitert (additiv — ohne Parameter KEIN Attr-Rendering, abwärtskompatibel getestet) + neuer block_instance-Case: Attr-Werte als text-Primitives gestaffelt unterhalb der Instanz-Position (8px + 16px/Zeile, tag=Wert-Format, Fallback auf defaultValue, — als letzter Fallback); (3) PropertiesPanel: Block-Attribute-Formular für selektierte block_instances — attrDefs-Lookup über documentService.getActiveDocument().getBlock(blockId), editierbare Textfelder je tag mit prompt als Placeholder, Schreibzugriff über onUpdateProperty(attrValues, next) mit Shallow-Merge; DXF-ATTDEF/ATTR-Roundtrip war bereits durch F5 (Parser) + F6 (Writer) abgedeckt | Frontend: 697/697 Tests (+7 blockAttributes.test.ts), tsc 0, Build EXIT 0 | 9ca86d6 | **D12 COMPLETE — PHASE D VOLLSTÄNDIG** (alle D1–D12: Ellipse, Spline, Konstruktion, MTEXT, Stretch/Break/Join/Chamfer/Lengthen/PolylineEditor/Explode/Align verifiziert, GripEditing, Arrays rect/polar/path, Snaps erweitert, BlockAttribute); nächster Schritt: Phase I (I2 Docs zuerst) |
+| 2026-08-29 | D11 | Snap-Erweiterungen: (1) collectQuadrant NEU — Kreis/Arc-Quadrantenpunkte 0°/90°/180°/270° auf dem Radius (4 Checks je Element); (2) collectPerpendicular NEU — Perpendicular-Fußpunkt: Punkt auf einem Segment (line-Props oder polyline-Segmente), an dem die Verbindung zum refPoint SENKRECHT steht (nearestOnSegment vom refPoint), still ohne refPoint (Modus braucht aktiven Zug); (3) collectTangent NEU — Berührpunkte der Tangenten vom refPoint an den Kreis über rechtwinkliges Dreieck: halfAng = acos(r/d), BEIDE Lösungen als Kandidaten, Degenerations-Guard d≤r (refPoint im Kreisinneren/Zentrum → keine Tangente); (4) fromOffset NEU als reine exportierte Funktion (Basispunkt + dx/dy für das from-offset-UI); (5) snap()-Schleife erweitert (perpendicular/tangent nur mit refPoint) + Prioritäts-Map erweitert (quadrant zwischen center und perpendicular); SnapPoint-Typ unterstützte perpendicular/tangent/quadrant bereits (C3fin-Typunion vorbereitet — nur die Collects fehlten); Test-Zwischenfall selbst erkannt: mein erster Tangenten-Test erwartete (150,100) — das ist der Kreis-Scheitel Richtung refPoint, NICHT der Tangentenpunkt (Tangente steht senkrecht auf dem Radius!); echte Tangentenpunkte bei d=100/r=50: halfAng=60° → (125,143.3)/(125,56.7) — Test auf echte Geometrie korrigiert | Frontend: 690/690 Tests (+12 snapExtensions.test.ts), tsc 0, Build EXIT 0 | c4e3206 | D11 COMPLETE; nächster Task D12 (BlockAttribute — letztes D-Tool) |
+| 2026-08-29 | D10 | array-path als D10-Rest komplett: arrayPathTool NEU in core-modify — Klick1: Quelle (Auto-HitSelect bei leerer Selektion wie array-rect/polar), Klick2: muss eine Polyline/Polygon als Pfad treffen (Typ-Validierung + Punkteanzahl-Check, sonst Status-Erklärung ohne Commit); pointAlongPolyline-Helfer: Punkt bei kumulierter Pfadlänge s über Segment-Iteration (Clamp an Enden); Verteilung: count Kopien bei s = i/(count-1)·total (Default count=5, Option 2–100) — gleichmäßig über die GESAMTE Pfadlänge inkl. Endpunkte, gebogene/L-förmige Pfade folgen der Geometrie (Winkel-Test: alle Kopien auf dem Pfad); Pfad-Element selbst wird NICHT kopiert (Filter aus Selektion); ALLES in EINER doc.transact = 1 Undo (Undo-Test: alle Kopien in einem Schritt weg); Original bleibt unangetastet | Frontend: 678/678 Tests (+8 arrayPath.test.ts), tsc 0, Build EXIT 0 | 227d617 | **D10 COMPLETE — alle drei Array-Typen (rect/polar/path) implementiert**; Dialog+Vorschau für Arrays als UI-Follow-up notiert; nächster Task D11 (Snaps erweitern) |
+| 2026-08-29 | D9 | GripEditing im select-Tool: (1) getGripPoints NEU als reine exportierte Funktion — element-spezifische Griff-Punkte: line = beide Endpunkte (vertex), polyline/polygon = alle Vertices (vertex), circle/arc = Zentrum (center), rect/default = 4 BBox-Ecken (corner — C3fin-Skalierung bleibt unverändert parallel bestehen); (2) Vertex-Drag-Sitzung im select-Tool — down prüft Vertex-/Center-Grips VOR den BBox-Corners (spezifischer gewinnt bei Überlappung — der Test verifiziert eine line deren Endpunkt AUCH BBox-Ecke ist: Vertex-Drag wirkt, kein Scale), move zeigt Live-Preview (nur der Punkt aktualisiert), up committet doc.updateElement in EINER Transaktion = 1 Undo-Schritt (Undo-Test stellt Endpunkt exakt wieder her), cancel resettet beide Drag-Typen; (3) applyVertexDrag als reine Funktion für Preview UND Commit (line: Endpunkt + BBox-Sync, polyline: nur Vertex + BBox-Sync, center: nur x/y, Radius unberührt — Radius-Bleibt-Test verifiziert) | Frontend: 670/670 Tests (+11 gripEditing.test.ts), tsc 0, Build EXIT 0 | c6f38ee | D9 COMPLETE; nächster Task D10-Rest (array-path) |
+| 2026-08-29 | D4 | MTEXT-Tool: mtextTool NEU in core-annotate v1.1.0 — Klick platziert mehrzeiligen Text (Inhalt aus Options-Feld, Zeilenumbrüche via charCode-10-Split konsistent zur F5-Parser-MTEXT-Konvention, mtext:true-Marker); fontSize-Option (Default 12, min 6, max 72); frame-Checkbox-Option erzeugt zustzliches rect-Element in derselben doc.transact (Text + Rahmen = 1 Undo-Schritt, Undo-Test verifiziert BEIDE weg); RahmengröÜe aus längster Zeile×fontSize×0.6 Breite und Zeilenzahl×fontSize×1.4 Höhe plus Padding (Höhen-Wachstums-Test verifiziert); OptionsSchema mit text/number/checkbox-Feldern; tools-Array: textTool, dimensionTool, leaderTool, mtextTool | Frontend: 659/659 Tests (+7 mtextTool.test.ts), tsc 0, Build EXIT 0 | fbc4978 | D4 COMPLETE; nächster Task D9 (GripEditing) |
+| 2026-08-29 | D3 | Konstruktions-Elemente: (1) CADDocument.addLayer additiv NEU (Überschreiben gleicher ID, kein Undo-Schritt — für Auto-Anlegen von Hilfs-Layern); (2) ensureDefpointsLayer-Helfer legt defpoints-Layer (dotted, grau #8a8f98, transparency 0.5, sortOrder 999) automatisch an, falls fehlt; (3) pointTool: Klick-Platzierer — kleiner Kreis r=1.5 mit point:true-Marker (identische Konvention zum F5-Parser DXF-POINT-Import); (4) xlineTool: 2-Klick (Basis + Richtung) → Linie der Länge 2×100000 SYMMETRISCH um den Basispunkt (beidseitig unendlich), normierter Richtungsvektor, degenerierte Klicks (len<0.001) still verworfen; (5) rayTool: gleiche Struktur, aber Linie NUR in Klickrichtung ab Basis (100000 in eine Richtung); alle drei mit construction:true-Tags auf defpoints-Layer, Preview bei move (xline/ray), cancel-Reset; core-drawing v1.5.0 jetzt 12 Tools; Test-Zwischenfall: eigene Grenzwert-Assertion erwartete >100000 obwohl der Strahl exakt bei 100000 endet — auf >= korrigiert | Frontend: 652/652 Tests (+10 constructionTools.test.ts), tsc 0, Build EXIT 0 | bfd500b | D3 COMPLETE; nächster Task D4 (MTEXT-Tool) |
+| 2026-08-29 | D2 | Spline-Tool: splineTool NEU in core-drawing v1.4.0 — CV-basierte Zeichnung wie polyline (Klick-Sequenz sammelt Kontrollpunkte, ENTER committet ab 3 CVs mit boolean-Konsum, Nicht-ENTER-Keys return false); catmullRom-Helfer: Interpolation DURCH alle CVs (nicht approximierend wie de-Boor im F5-Parser — hier gewollt, da Nutzer die Kurve durch geklickte Punkte erwartet), Tangenten aus Nachbar-CVs (Endpunkte geklemmt), 16 Samples pro Segment → deutlich mehr Punkte als CVs mit echter Glättungs-Schwingung an Ecken (S-Form-Test verifiziert overshoot); controlPoints in properties gespeichert (DXF-SPLINE-Export-ready — F5 kennt die Form bereits); Preview bei move über buildSpline mit Cursor als zusätzlichem CV; Session-State mit cancel-Reset; core-drawing jetzt 9 Tools | Frontend: 642/642 Tests (+10 splineTool.test.ts), tsc 0, Build EXIT 0 | fa3dc7d | D2 COMPLETE; nächster Task D3 (Point/XLine/Ray) |
+| 2026-08-29 | D1 | Ellipse+Bogen-Tool: ellipseTool NEU in core-drawing v1.3.0 — 3-Klick-Interaktion (Klick1=Zentrum, Klick2=RadiusX wobei die Zugrichtung die Rotation definiert (atan2 → Grad, 0°=+x), Klick3=RadiusY); buildEllipse-Helfer erzeugt Polyline-Approximation konsistent zur F5-Parser-Konvention: Voll-Ellipse → 64 Punkte als geschlossenes polygon, Ellipsenbogen (startAngle/endAngle-Options) → proportional offene polyline (32 Punkte bei 180°); Metadaten cx/cy/rx/ry/rotation (+startAngle/endAngle bei Bogen) in properties — D12/DXF-Export-ready; Preview bei move in beiden Phasen (RadiusX als Kreis-Approximation, Phase 2 mit live RadiusY); Session-State als Modul-Members mit cancel-Reset; Status führt durch Phasen; erste Implementierung hatte einen überkomplexen Rotation-Ansatz über ctx-Hack — beim Schreiben selbst vereinfacht zu direktem ellipseRotationDeg-Session-Merker | Frontend: 632/632 Tests (+8 ellipseTool.test.ts), tsc 0, Build EXIT 0 | 5db421d | D1 COMPLETE; nächster Task D2 (Spline-Tool) |
+| 2026-08-29 | H5 | Flächenberechnung: (1) polygonArea NEU in geometry.ts — Shoelace-Formel mit Absolutwert (Uhrzeigersinn und gegen Uhrzeigersinn ergeben dasselbe, getestet), <3 Punkte/kollinear → 0; (2) formatArea NEU in utils/format.ts — analog formatDistance aber QUADRATISCHE Skalierung (raw × scaleFactor² = mm²), mm/cm/m-Formatierung (5000 mm² / 50.0 cm² / 5.00 m²); (3) measure-area Tool NEU in core-measure (Status-only wie measure, KEIN Element-Commit): Klick fügt Punkt hinzu, move zeigt Live-Fläche über Polygon+Cursor, ENTER committet ab 3 Punkten (boolean-Rückgabe konsumiert), cancel resettet Module-State; optionsSchema unit (select mit korrektem options-Array) + scaleFactor; (4) PropertiesPanel zeigt Flächenzeile für polygon/polyline ab 3 Punkten (unit + scaleFactor aus Props); Test-Fix selbst erkannt: eigene Erwartung linear statt quadratisch skaliert + Dreieck- statt Quadrat-Fläche + Module-State-Leak zwischen Tests (beforeEach-Reset via cancel) | Frontend: 624/624 Tests (+14 measureArea.test.ts), tsc 0 (nach 2 selbst gefixten Typ-Fehlern: PropertyField heißt options nicht values, key-Handler braucht boolean), Build EXIT 0 | b210ccc | **H5 COMPLETE — PHASE H VOLLSTÄNDIG** (Modi/Templates/Rollen/i18n/Flächen); nächster Schritt: Rest-D-Tools ab D1 (Ellipse) |
+| 2026-08-29 | H4 | i18n-Grundlage: (1) src/i18n/strings.ts NEU — zentrale DE/EN-Maps (Key-Pfad → String oder parametrisierte Funktion für dynamische Texte wie „Layout X löschen“), t(key, arg) mit Key-Fallback bei unbekannten Keys (offensichtlich sichtbar statt still), LANGUAGES-Konstante, getLanguage/setLanguage mit localStorage-Persistenz (webcad.language, Default de, ungültige Werte → de) analog uiModeService-Muster, subscribeLanguage-Set, useT-React-Hook erzwingt Re-Render bei Sprachwechsel; (2) Kern-UI-Texte auf t() umgestellt: LayoutBar (Titel, Hinzufügen, Leer, Löschen, Drucken, Titelblock, Zoom-to) + Topbar-Modus-Toggle (title + aria-label) — mit echtem Live-Wechsel getestet (de → en im laufenden Render); (3) vollständige mechanische Ersetzung ALLER Komponenten-Texte bewusst als teilautomatisierbares Follow-up markiert (Roadmap-Wortlaut); Zwischenfälle selbst behoben: Python-Quoting-Abbruch beim ersten Implementierungsversch (strings.ts wurde nicht geschrieben, Komponenten referenzierten useT schon → nachgetragen) + Testing-Library-State-Update außerhalb act() (Sprachwechsel im Test in act() gewrappt) | Frontend: 610/610 Tests (+8 i18n.test.tsx), tsc 0, Build EXIT 0 | e6fdb39 | H4 COMPLETE; nächster Task H5 (Flächenberechnung Polygon m² + measure-area Tool) |
+| 2026-08-29 | H3 | Rollen library-admin vs. user: requireLibraryAdmin NEU in authMiddleware (an bestehende admin-Rolle gebunden — bewusst KEINE neue DB-Rolle, bestehendes users.role CHECK admin/planer/betrachter/gast bleibt unverändert); alle 8 schreibenden Global-Library-Routen auf requireLibraryAdmin umgestellt (POST/PATCH/DELETE /api/global-folders, POST/PATCH/DELETE /api/global-blocks, POST import, POST import-zip); Lesen (GET folders/blocks/export/export-zip) bleibt für ALLE authentifizierten Nutzer offen (planer kann Konsumieren aber nicht die globale Bibliothek verändern); zeichnungsscoped blocks-Routen unangetastet (per-drawing ownership dort); Fehlermeldung 403 „Library admin access required"; Test-Zwischenfall selbst erkannt: Header-Konstanten im describe-Body capturen undefined (describe-Body läuft VOR beforeAll) — nach Token-Debug (Länge undefined) Header-Objekte in beforeAll-Zuweisung umgestellt, dann sauberes ROT (8 Schreib-Tests) → GRÜN | Backend: 287/287 Tests (+14 libraryAdminGuard.test.ts: 3 Lese-für-planer, 8×403-Schreiben-für-planer, 2 Admin-201, 1 Unauth-401), BE tsc 0 | d403040 | H3 COMPLETE; nächster Task H4 (i18n-Grundlage) |
+| 2026-08-29 | H2 | Projekt-Templates: projectTemplates.ts NEU — ProjectTemplate-Typ (id/name/description/gridSize/unit/layers/enabledPlugins/libraryFolderSeed) + 6 Branchen-Presets als TS-Konstanten (JSON-äquivalent, ohne Datei-IO direkt tree-shakebar): halle (Veranstaltungshalle, 100cm-Raster, Wände/Bestuhlung/Bühne/Technik, event-tools), openair (Zonen/Bestuhlung/Absperrung/Wege, event-tools), saal (Bestuhlung/Bühne/Catering/Deko, 50cm), messe (Standlayout/Theken/Medien/Strom, 10mm), büro (Wände/Möbel/Netzwerk/Beschriftung, 10mm), garten (Bepflanzung/Wege/Wasser/Beleuchtung, 100cm) — je 4 Layer mit eindeutigen tpl-*-IDs, enabledPlugins inkl. core-*/builtin-library; applyProjectTemplate überträgt Layer-Set ERSETZEND (Template = Startzustand) via neuem CADDocument.replaceLayers (transaktionsgebündelt: alle deletes+sets in EINER Transaktion = 1 Undo-Schritt); gridSize/unit/pluginSeed sind UI-Einstellungen, die der Aufrufer aus dem Template liest (Dokumentation im Service) | Frontend: 602/602 Tests (+6 projectTemplates.test.ts), tsc 0, Build EXIT 0 | 131a922 | H2 COMPLETE; nächster Task H3 (Rollen library-admin vs. user, Backend-Guard) |
+| 2026-08-29 | H1 | simple/pro Mode: (1) uiModeService NEU — getUIMode/setUIMode/toggleUIMode/subscribeUIMode + useUIMode-React-Hook; localStorage-Persistenz (webcad.uiMode, Default pro, ungültige Werte → pro-Fallback, try/catch für nicht verfügbares localStorage); BEWUSST kein zustand-Store (Q2-Entscheidung wurde nie umgesetzt, kein stores/-Verzeichnis vorhanden) — Service folgt dem etablierten documentService/featureFlags-Muster des Projekts; (2) RibbonBar: V2-Tool-Sektion filtert im simple-Modus auf manifest.tags includes basic (useUIMode-Hook, Live-Update bei Toggle); (3) CommandLine: useUIMode → simple rendert null (pro-only); (4) Topbar: Toggle-Button 😊(→simple)/🛠(→pro) in topbar-right; Test-Zwischenfälle: CommandLine-Root-Klasse heißt .cmdline nicht .command-line (Selektor fixiert), Topbar braucht Pflicht-Props (Test-Render angepasst) | Frontend: 596/596 Tests (+9 uiMode.test.tsx), tsc 0, Build EXIT 0 | 8774fea | H1 COMPLETE; nächster Task H2 (Projekt-Templates) |
+| 2026-08-29 | G5 | Browser-Print stylesheet: (1) @media print Block in styles.css — @page size A4 landscape margin 10mm; .screen-only display none !important (UI-Chrome); .print-area width/height 100% overflow visible (Druckbereich füllt Seite); .print-layout * -webkit-print-color-adjust + print-color-adjust exact (Farben/Linien wie angezeigt drucken); body weiß + overflow hidden; (2) printService NEU — preparePrintLayout setzt body.print-layout-Klasse, cleanupPrintLayout entfernt (kein DOM-Restzustand), printLayout: prepare → 2× requestAnimationFrame (Styles greifen vor Print-Dialog) → window.print → finally-cleanup (auch bei Abbruch); (3) LayoutBar-Druck-Button 🖨 ruft printLayout (screen-only-Klasse); Tests: Service-Interaktion (Klasse setzen/entfernen, print-Spy + Cleanup) + CSS-Datei-Assertions (@page-Regex, screen-only/print-area-Regeln, print-color-adjust) | Frontend: 587/587 Tests (+7 printStylesheet.test.ts), tsc 0, Build EXIT 0 | d9a0dff | **G5 COMPLETE — PHASE G VOLLSTÄNDIG** (Layouts & Plot: G1 Datenmodell, G2 LayoutBar, G3 Titelblock, G4 PDF, G5 Print); nächster Schritt: Phase H ab H1 (simple/pro Mode) |
+| 2026-08-29 | G4 | PDF-Export je Layout: exportLayoutPDF(doc, layoutId, options{monochrome,margin}) NEU in pdfExport.ts (additiv — Legacy-exportPDF unangetastet): A4 landscape 842×595pt; Ausgabemaßstab = layout.viewport.scale, sichtbarer Welt-Ausschnitt aus center berechnet; Y-Flip (PDF bottom-left vs CAD top-down) in toPage-Transform; Rendering über elementToPrimitives (C2) statt duplizierter Typ-Switches → garantiert identische Konventionen wie Pixi-Renderer (Legacy-exportPDF hätte Circle um width/2 verschoben gezeichnet — gleiche Bugklasse wie DXF-Writer vor F6, dort belassen und im Log vermerkt); Linienbreiten: properties.strokeWidth sonst Layer-lineType (solid 0.7pt/dashed 0.9pt/dotted 0.5pt) mit Dash-Patterns [4,3]/[0.5,2]; monochrome erzwingt rgb(0,0,0) + keine Dashes; unsichtbare Layer gefiltert; Arc→32 Segmente (Grad CCW); Titelblock aus frameBlockRef wird unskaliert unten-rechts mitgezeichnet (Block-Elemente um Ursprung an Ecken-Offset); drawPrimitive deckt alle 6 Primitive-Kinds | Frontend: 580/580 Tests (+6 pdfLayoutExport.test.ts — PDF via PDFDocument.load verifiziert: Seitenzahl 1, Größe 842×595, Frame-Block-Fall, monochrome, leerer Viewport, unknown-ID-throw, unsichtbare Layer), tsc 0, Build EXIT 0 | cb23638 | G4 COMPLETE; nächster Task G5 (Print-Stylesheet) |
+| 2026-08-29 | G3 | Titelblock-Block mit Attributen: (1) titleBlockService NEU — createTitleBlockElements (reine Funktion): Rahmen rect 180×100 (App-Konvention x/y=Zentrum) + Titel-Label + 4 attributierte Texte PROJEKT/DATUM/MASSSTAB/AUTOR mit tag/attdef:true/prompt-Metadaten und text=TAG=Wert (exakt die F5-Parser- und F6-Writer-Konvention → DXF-ATTDEF-Roundtrip & D12-Formular-ready), leere Meta → Fallback —; (2) insertTitleBlockForLayout: Blockdefinition (category frame) via doc.addBlock + frameBlockRef im Layout via updateLayout, Re-Insert ersetzt Referenz (neue Block-ID), fehlendes Layout → throw; (3) CADDocument um getBlock/addBlock erweitert (bewusst NICHT undo-getrackt — konsistent zum UndoManager-Design-Kommentar); (4) LayoutBar-Button 🏷 je Layout: fügt/aktualisiert Titelblock mit Layout-Name als Projekt, heutiges Datum, Maßstab aus viewport.scale (1:1/scale gerundet), Autor WebCAD; Test-Zwischenfall: eigene Assertion prüfte attdef über alle 5 Texte inkl. Titel-Label (bewusst kein Attribut) — auf getaggte Texte gescoped | Frontend: 574/574 Tests (+6 titleBlock.test.ts), tsc 0, Build EXIT 0 | bbb469e | G3 COMPLETE; nächster Task G4 (PDF-Export je Layout) |
+| 2026-08-29 | G2 | LayoutBar UI + Viewport-Widget: (1) ZoomPanController.setView(center, scale) NEU — Welt-Punkt exakt ins Canvas-Zentrum bei Scale, geclamped 0.01–100; (2) LayoutBar-Komponente: listet Layouts des aktiven Docs (documentService-Fallback mit onActiveDocumentChanged-Subscription + onChanged-Live-Reload), je Eintrag SVG-Minimap (Modellbereich als Rechteck + Viewport-Ausschnitt blau — scale-abhängig sichtbar kleiner), Klick = zoom-to via Bridge, „+“ speichert aktuellen Viewport als Layout, 🗑 löscht; (3) computeMinimapRects als reine exportierte Funktion (Modell-BBox füllt Widget mit 6px Padding, ohne Elemente Volles-Widget-Fallback, Viewport = 800×600/scale nominal); (4) CanvasArea-__v2LayoutBridge nach E6b-Muster (zoomTo mit render-Trigger, getView aus getViewport+getScale); (5) App.tsx mountet LayoutBar über StatusBar; CSS angehängt; Zwischenfälle selbst gefixt: view-Parameter-Kollision in computeMinimapRects (Umbenennung viewRect) + Regex-Double-Escape im Test | Frontend: 568/568 Tests (+11 layoutBar.test.tsx), tsc 0, Build EXIT 0 | 7feed9e | G2 COMPLETE; nächster Task G3 (Titelblock-Block mit Attributen auto-insert) |
+| 2026-08-29 | G1 | Layout-Datenmodell: LayoutViewport {center{x,y}, scale} + LayoutDefinition {id, name, viewport, frameBlockRef?} in cad.types.ts; YjsDocument.data um layouts-Map (YjsDocumentData-Interface additiv erweitert + getLayouts-Getter); CADDocument um Layout-CRUD erweitert: getLayout/getAllLayouts/addLayout/updateLayout (Top-Level ersetzt, viewport + center SHALLOW gemergt — center/scale einzeln änderbar, frameBlockRef bleibt bei reinem name-Patch erhalten)/deleteLayout (still bei unbekannter ID); Y.UndoManager um layouts-Map getrackt → jedes add/update/delete = eigener Undo-Schritt (2-Schritte-Undo-Test: add→delete→undo→undo verifiziert); Persistence läuft automatisch über bestehende drawing-json-Serialisierung (Y-Doc-Snapshot) | Frontend: 557/557 Tests (+6 layouts.test.ts), tsc 0, Build EXIT 0 | e750a45 | G1 COMPLETE — Datenmodell steht; nächster Task G2 (LayoutBar UI + Viewport-Widget) |
+| 2026-08-29 | E7 | Event-Elemente-Polish: (1) ElementType um curtain/spotlight/barrier erweitert (cad.types.ts additiv); (2) Pixi-Drawer-Cases: curtain = wellige Polyline aus properties.points (24 Punkte, Sinus gedämpft, close=false; Fallback Linie), spotlight = Kegel-Polygon aus points (close=true, stroke=properties.color), barrier = Kreis-Paare aus properties.circles (12 Kreise, Fallback 5 entlang BBox); (3) Platzier-Tools via Klick: curtainTool (stageHeight-Option, Standard 120cm, Breite 400), spotlightTool (angle+color-Optionen, Länge 300, Öffnung ±20°, Grad-Winkel direkt — Konvention konsistent zu F6), barrierTool (length-Option, Standard 200, 6 Kettenglieder); (4) createStage um properties.height (Bühnenhöhe in cm) erweitert; event-tools v2.2.0, tools-Array jetzt 13 Einträge; Test-Helper fireDown auf etabliertes Pilot-Muster umgestellt (echtes CADDocument aus createInMemoryDoc statt Broken-Mock ohne transact — 7 Tests rot wegen Mock, nach Muster-Fix grün) | Frontend: 551/551 Tests (+8 eventPolish.test.ts), tsc 0, build OK | 9176d7c | **E7 COMPLETE — PHASE E VOLLSTÄNDIG**; nächster Schritt: Phase G (Layouts & Plot) ab G1 |
+| 2026-08-29 | D-VERIF | Phase-D-Checklisten-Diskrepanz geklärt: D5 (stretchTool), D6 (breakTool+joinTool), D7 (chamferTool/lengthenTool/explodeTool/alignTool), D8 (polylineEditTool) gegen Code verifiziert und abgehakt — alle im core-modify tools-Array (22 Tools) registriert, Log-Einträge D-fin/D-ext/D-ext3 dokumentieren Implementierung mit grünen Tests; D10 angepasst: array-rect/polar erledigt, array-path + Dialoge bleiben offen; tatsächlich noch offen: D1 (Ellipse-Tool), D2 (Spline-Tool), D3 (Point/XLine/Ray), D4 (MTEXT-Tool), D9 (GripEditing), D10-Rest (array-path), D11 (Snaps), D12 (BlockAttribute) | — (reine Verifikation/Doku, kein Code geändert) | — | Kein Commit nötig — ROADMAP-Doku |
+| 2026-08-29 | F8 | SVG-Import als Block: (1) parsePathData NEU — Tokenizer für d-Attribut mit allen Befehlen M/L/H/V/C/S/Q/T/A/Z (absolut+relativ), implizite Befehlswiederholung, M→L-Fortsetzung; kubische/quadratische Bézier geflattet (16/12 Segmente), Arc über Endpoint→Center-Parametrisierung (SVG Spec F.6.5, 32 Samples, Endpunkt exakt statt Float-Rundung), Z→geschlossen ohne duplizierten Endpunkt, Mehrfach-Subpaths; (2) Konventions-Fixes: rect x/y jetzt Zentrum (App-Konvention), circle el.x/el.y direkt Zentrum statt cx-r (Renderer lesen es so — gleiche Bugklasse wie DXF-Parser vor F6), ellipse jetzt echtes 64-Punkt-geschlossenes Polygon statt verstümmeltem Kreis max(rx,ry); (3) importSVGAsBlockPayload NEU: echte Geometrie als JSON-Array + Original-SVG als Thumbnail, null-Fallback auf {type:svg}-Raw wenn keine Geometrie; BlockLibraryTree SVG-Import (Toolbar + Folder-Drop) nutzt Geometrie-Payload bevorzugt | Frontend: 543/543 Tests (+11 svgImportF8.test.ts), tsc 0, build OK | 09948bc | **F8 COMPLETE — PHASE F VOLLSTÄNDIG ABGESCHLOSSEN** (Library & Import/Export: F1–F8 alle grün); nächster Schritt: Phase-D-Checklisten-Diskrepanz klären, dann E7 |
+| 2026-08-29 | F7 | .wcadlib als echtes ZIP-Paket: (1) Backend GET /api/global-blocks/export-zip — JSZip generiert manifest.json (format wcadlib-zip v1, exported_at, counts), blocks.json (Ordner + Blöcke mit thumbnail-Referenz) und thumbs/<blockId>.svg je SVG-Thumbnail; content-type application/zip + content-disposition attachment; (2) POST /api/global-blocks/import-zip — JSZip.loadAsync, Validierung (kein ZIP → 400, blocks.json fehlt → 400, invalides JSON → 400, manifest.format≠wcadlib-zip → 400), Ordner-Import mit Eltern-zuerst-Sortierung + ID-Mapping, Thumbnail aus thumbs/ referenzgelesen, 201 mit imported_blocks/imported_folders; (3) Fastify addContentTypeParser application/zip + octet-stream + x-zip-compressed als Buffer (Server-Global); (4) Frontend exportLibraryZip/importLibraryZip in api.ts (Blob-Download, Upload mit content-type application/zip), zwei neue Toolbar-Buttons (ZIP-Box-Icons) + hidden file-input in BlockLibraryTree; F1-JSON-Variante bleibt parallel bestehen | BE: 272/272 Tests (+5 globalBlocksZip.test.ts), BE tsc 0; FE: 532/532, FE tsc 0, build OK | d311820 | F7 COMPLETE — ZIP-Roundtrip mit echten write→read-Roundtrip-Tests (Export→Import→DB-Verifikation) |
+| 2026-08-29 | F6 | DXF-Writer erweitert: (1) BLOCKS-Sektion mit sanitierten Blocknamen (Leerzeichen→Unterstrich, Kollisions-Dedup, 0 reserviert) + Name-Map blockId→DXF-Name; INSERT referenziert gemappten Namen mit scaleX/scaleY (Fallback scale) + Rotation in Grad direkt; (2) ATTDEF-Emission in Blockdefinitionen (text-Elemente mit attdef:true+tag → ATTDEF mit tag/prompt/textHeight); ATTRIB/SEQEND + Gruppe-66 an Instanzen mit attrValues; (3) DXFWriterOptions.version AC1009(R12)-Default/AC1015 im Header; (4) R12-korrektes POLYLINE+VERTEX+SEQEND statt LWPOLYLINE (erst ab R13) inkl. rect-Zentrums→Ecken-Konvertierung und BBox-Fallbacks; **ROUNDTRIP write→parse aufgedeckte 3 latente Bugs, alle gefixt**: Writer circle-Center war x+width/2 obwohl beide Renderer el.x/el.y ALS Zentrum lesen (exportierte Kreise wanderten); Parser CIRCLE/ARC mappten auf min-corner statt Zentrum (importierte Kreise verschoben); dxf-parser liefert ARC-Winkel intern in Radiant, App nutzt Grad → toDeg-Fix im Parser-ARC-Zweig (importierte Bögen falsch); block_instance ohne Blockdef → BBox-Fallback statt blindem INSERT | Frontend: 532/532 Tests (+13 dxfWriterF6.test.ts), tsc 0, build OK | 75de6dd | F6 COMPLETE — DXF-Roundtrip (F5-Import + F6-Export) Ende-zu-Ende mit echten Roundtrip-Tests geschlossen; nächster Task: F7 (.wcadlib ZIP-Paket) |
+| 2026-08-29 | F5 | DXF-Parser erweitert: (1) ELLIPSE → Polyline-Approx (64 Segmente Voll-Ellipse, partiell proportional, Rotation über majorAxisEndPoint, außerhalb 0..2π normalisiert); (2) SPLINE Grad≤3 → Cox-de-Boor-Approximation (40 Punkte, Default-Knotenvektor wenn knotValues fehlen, Grad>3 → skip mit Report-Grund); (3) MTEXT → text-Element mit Formatcode-Cleanup (\P→Zeilenumbroch, Inline-Codes \A1;/\H2x; entfernt); (4) POINT → Markerkreis r=1.5 mit point-Marker; (5) ATTDEF → text tag=Wert mit tag/prompt/attdef-Metadaten; (6) HATCH → polygon mit hatchPattern (forward-kompatibel via Entity-Injektion getestet, da dxf-parser 1.1.x echte HATCH nicht durchreicht); INSERT erweitert: MINSERT-Arrays (columnCount/rowCount/spacing) via neuem expandInsert, scaleX/scaleY getrennt; DXFImportResult um skippedEntities {type,reason} erweitert, skipReason-Fabrik je Typ, LINE-BBox-Form vereinfacht (minXY+abs); WARNUNG dokumentiert: dxf-parser verschluckt völlig unbekannte Typen (FOOBAR-Report-Test ersetzt durch validen Grad-4-SPLINE, der die Library passiert und gemappt skippt) | Frontend: 519/519 Tests (+16 dxfParserF5.test.ts), tsc 0, build OK | 6857694 | F5 COMPLETE; Zwischenfall: erster Suite-Lauf hing in dxf-parser-Endlosschleife bei malformed LINE-Test-STRING (nicht unserem Code) — Test auf validen SPLINE-Grad-4-Fall umgestellt, Escape-Fehler in Testdatei selbst erkannt und repariert; nächster Task: F6 (DXF Writer erweitern) |
+| 2026-08-28 | F4 | LibraryProviderExtension angeschlossen: (1) builtinLibraryPlugin (V2, category library, enabledByDefault) mit builtin-catalog-JSONs event/architecture/landscape je 15 Blöcken (Stühle, Tische, Bühnen, Türen, Fenster, Bäume u.a.) als statische Startersets unter plugins/builtin/library/catalogs/; (2) makeUserLibraryProvider (zeichnungsscoped Drawing-Blöcke, elements_json-Parsing inkl. Wrapped-Form); (3) makeGlobalLibraryProvider (global-blocks API gegen Token, Ordnerhierarchie); LibBlock um optionales payload-Feld erweitert (JSON-String CADElement-Array) — Panel nutzt den bestehenden text/global-block-data Drop-Kanal, CanvasArea unverändert; LibraryProviderPanel-Komponente (Sektionen je Ordner, SVG-Thumbnails via generateBlockSvg mit Cache, DragSource-Buttons); RightSidebar-Memo vereint Registry-Provider + builtin + user + global mit Dedup; Doppel-ID a2c im architekt-Katalog beim Schreiben selbst korrigiert (a2d); Duplikat-Provider via pluginRegistry UND direktem builtinCatalogProvider-Fallback ausgeschlossen (Set-Dedup in RightSidebar) | Frontend: 503/503 Tests (+8 libraryProviders.test.tsx), tsc 0, build OK | 2efbbf9 | F4 COMPLETE — drei Bibliotheksquellen Ende-zu-Ende: builtin/user/global mit DragDrop ins Canvas; nächster Task: F5 (DXF Parser erweitern) |
+| 2026-08-26 | PLAN | ROADMAP.md erstellt, Baseline analysiert | tsc 0, FE 380✓, BE 255✓ | — | Ausgangszustand dokumentiert |
+| 2026-08-26 | B0 | bugs.regress.test.ts angelegt (3 Tests für BUG-1/1b/2); alle 3 ROT wie vorhergesagt; Rest-Suite unverändert grün; Validierung des Dokuments bestanden | FE 380✓ + 3 rot (erwartet), tsc 0 | b9eb69f | Nächster Task: B1 |
+| 2026-08-26 | B1 | nextUid-Helper eingebaut; createSeatingRow rowId vor Schleife; createSeatingBlock blockId via nextUid + rowId pro Reihe in properties | BUG-1+1b GRÜN, 382/383 gesamt (BUG-2 rot wie erwartet), tsc 0 | 1bbd653 | Nächster Task: B2 |
+| 2026-08-26 | B2 | lineCircleIntersections/circleCircleIntersections/lineArcIntersection implementiert; findIntersection auf Typ-Dispatch erweitert; Guards in trim/extend von Truthiness auf undefined korrigiert (Koordinate 0 war falsy); Tangenten-Dedup; 10 neue Unit-Tests | ALLE GRÜN: 393/393 gesamt, tsc 0 | 95b14cf | Nächster Task: B3 |
+| 2026-08-26 | B3 | offsetElement um side-Parameter erweitert (rückwärtskompatibel); Interaktionszweig nutzt Kreuzprodukt (Linie) bzw. Radius-Vergleich (Kreis/Bogen); 4 neue Tests | ALLE GRÜN: 397/397 gesamt, tsc 0 | d8f29e4 | Nächster Task: B4 |
+| 2026-08-26 | B4 | drawBackground cached Bild pro backgroundSrc; kein new Image() pro Frame mehr; Regressionstest mit FakeImage-Zähler | ALLE GRÜN: 398/398 gesamt, tsc 0 | d93ee53 | Nächster Task: B5 |
+| 2026-08-26 | B5 | countSeats um optionales byZone erweitert; Testdatei seating.count.test.ts (5 Tests inkl. BUG-1-Verifikation im Block) | **PHASE B ABGESCHLOSSEN** — ALLE GRÜN: 403/403 gesamt, tsc 0 | 7f4768c | Nächster Task: A0 |
+| 2026-08-26 | A0 | logger.ts (Level-basiert, localStorage-konfigurierbar), MockRenderEngine (Recorder mit exakt den RenderEngine-Methoden von InteractionEngine), createInMemoryDoc (netzwerkfreie Yjs-Fabrik); 6 Smoke-Tests | ALLE GRÜN: 409/409 gesamt, tsc 0 | cba9358 | Nächster Task: A1 |
+| 2026-08-26 | A1 | Plugin-API v2 additiv: ToolManifestPart/ToolPointerEvent/ToolContext(inkl. setPreview?)/ToolExtensionV2/PanelExtension/LibFolder/LibBlock/LibraryProviderExtension/PluginV2; Registry um registerV2/enable/disable/isV2Enabled/getToolsV2/getToolV2/getPanels/getLibraryProviders erweitert, initDefaults deckt V2 ab; Public Exports ergänzt; 4 Tests (mit Singleton-Isolation via afterEach-Cleanup) | ALLE GRÜN: 413/413 gesamt, tsc 0 | 5d7fa23 | Nächster Task: A2 |
+| 2026-08-26 | A2 | InteractionDispatcher (dispatcher.ts: Event-Routing down/move/up/key/cancel an aktives ToolExtensionV2), pointer.ts (Event-Normalisierung screen→world über ZoomPanController.screenToWorld), session.ts (ToolSession-Guard gegen verlorene up-Events); CanvasArea instanziert Dispatcher hinter Flag VITE_TOOL_DISPATCHER=v2 inkl. destroy-Cleanup; 6 Tests (Reihenfolge, Session-Guard, ESC/Rechtsklick-cancel, setActive(null), Weltkoordinaten-Mapping) | ALLE GRÜN: 419/419 gesamt, tsc 0 | 4a7a8f9 | Nächster Task: A2b (CADDocument + UndoManager) |
+| 2026-08-26 | A2b | CADDocument-Fassade über YjsDocument: CRUD (getElement/getAllElements/getLayer/getAllLayers/addElement/updateElement mit Shallow-Merge/deleteElements), transact() Bündelung, undo/redo/canUndo/canRedo über Y.UndoManager MIT captureTimeout:0 (deterministische Schritte — Fix nach Test: Default-Merging fasste zeitnahe Transaktionen zusammen); onChanged-Subscription; 8 Tests (a–e gemäß Task + Grenzfälle) | ALLE GRÜN: 427/427 gesamt, tsc 0 | ddfeada | Nächster Task: A3 (Pilot-Migration select+line) |
+| 2026-08-26 | A3 | Pilot-V2-Tools: core-drawing (lineTool: down→Start, move→Live-Preview via setPreview, up→doc.transact=1 Undo-Schritt, cancel; Sitzungspunkt als Modul-Member statt Options-Store) und core-modify (selectTool: hitTest-basiert, Shift=additiv/Ctrl=subtraktiv/Leerklick leert); ToolContext um FullToolContext erweitert (doc?+selection? über ToolSelectionBridge), DispatcherDeps um getDoc/getSelectionBridge; beide Plugins enabledByDefault+tags basic, in registerBuiltinPlugins registriert; ÜBERGABE an A4: Browser-Verkabelung activeTool→setActive + yjsDoc→getDoc-Prop-Threading (App.tsx); 6 Tests (Line inkl. Undo-Akzeptanz, Cancel, Bridge-Auswahl Shift/Ctrl, Manifeste) | ALLE GRÜN: 433/433 gesamt, tsc 0 | 09a120d | Nächster Task: A4 (Restmigration, startet mit Verkabelung) |
+| 2026-08-26 | A4.1 | Verkabelung aus A3-Übergabe umgesetzt: CanvasArea instanziert lokales CADDocument (YjsDocument + layer-0 Seed) im Flag-Pfad; onChanged-Diff meldet neue Elemente über etablierten onElementCreated-Kanal an UI-State (announcedV2Ids-Guard gegen Doppelmeldung); DispatcherDeps getDoc/getSelectionBridge injiziert (Bridge auf SelectionEngine.getSelectedIds/selectByIds + RenderEngine.hitTest); activeTool-Effekt routet V2-bekannte Tools zusätzlich an dispatcher.setActive (Legacy parallel); Imports via src-crdt statt tests-Helfer (Produktcode rein halten) | 433/433 grün, tsc 0, vite build OK | d54a676 | Nächster Task: A4.2 (Restmigration Block 1: rect) |
+| 2026-08-26 | A4.2 | rectTool als erstes Rest-Migrationsmuster nach line-Vorlage portiert: rectStart-Sitzungs-Member, buildRect in Legacy-BBox-Konvention (x/y=Zentrum), Live-Preview, doc.transact-Commit, cancel; core-drawing v1.1.0 mit tools:[line,rect]; 2 Tests (BBox-Assertions inkl. undo, cancel) — MUSTER ETABLISIERT für übrige ~20 Tools: Legacy-Lesen → V2-Tool + build*-Helfer → Workflowtest mit Undo-Akzeptanz | ALLE GRÜN: 435/435 gesamt, tsc 0 | 8204de8 | Nächster Task: A4.3 (Block circle+arc gleiches Muster) |
+| 2026-08-27 | A4.3 | 4 Zeichen-Tools migriert: circle (Zentrum→Radius=Distanz), arc (3-Klick klick-progressiv — DESIGN-FIX nach Analyse: Commit im down statt up, weil Browser up immer direkt nach down feuert; Winkel via atan2 Grad CCW wie Legacy), polyline+polygon (Mehrklick-Punkte-Array, ENTER-Key-Handler committet ab 2 bzw. 3 Punkten, BBox-Zentrum); optsOf-Helfer konsolidiert stroke/layerId; Modul-Members arcPhase/arcCenter/arcStartPt/circleCenter/polyPoints; core-drawing v1.2.0 tools:[line,rect,circle,arc,polyline,polygon]; 5 neue Tests (Kreis undo, Arc Phasen+klick-progressiv+Cancel-Reset, Poly ENTER, Polygon-Mindestgrenze) | ALLE GRÜN: 438/438 gesamt, tsc 0 | 0dfe3b5 | Nächster Task: A4.4 (annotate: text/mtext) |
+| 2026-08-27 | A4.4 | core-annotate Plugin NEU: textTool (Einzelpunkt-Platzierung, fontSize via Options-Schema, Inhalt via bestehendem InlineTextEditor/onTextEdit-Kanal), dimensionTool+leaderTool über generische make2PointAnnotate-Fabrik (down→Preview→up commit, Legacy-Konventionen: dist als width bei dimension, text/fontSize/Properties bei leader); Registrierung in registerBuiltinPlugins; 3 Tests (dimension undo+x1..y2+Mitte, leader Konvention, text fontSize aus options) | ALLE GRÜN: 441/441 gesamt, tsc 0 | 239257c | Nächster Task: A4.5 (revcloud/hatch/measure) |
+| 2026-08-27 | A4.5 | revcloudTool in core-drawing (Poly-Muster mit ENTER ab 3 Punkten, Legacy arcHeight=8/fill none), core-measure Plugin NEU (measure = reine Status-Anzeige Distanz+Winkel via formatDistance(unit,scale) aus Options — bewusst KEIN Element-Commit wie Legacy, Format angle %\.1f\u00b0), hatchTool in core-modify v1.1.0 (hitTest→doc.updateElement hatch/hatchPattern/hatchSpacing aus Options —.undo-fähig statt Legacy-Callback; lehnt line mit Hinweis ab); CORE-MEASURE Importpfad-Fix nach tsc (3 Ebenen); Patch-Fehler in Testfile (Import durch describe ersetzt) sofort repariert; Registrierungen ergänzt; 4 neue Tests | ALLE GRÜN: 445/445 gesamt, tsc 0 | 464ddb9 | Nächster Task: A4.6 (Modify-Block move/copy/rotate/scale/mirror/delete) |
+| 2026-08-27 | A4.6 | makeMoveCopyTool-Fabrik NEU: move/copy wirken auf SELEKTION via SelectionBridge (Klick1=Basis+Auto-HitSelect bei leerer Selektion als Komfort, Klick2=Commit); move=updateElement x±dx/y±dy je Element, copy=addElement der Kopien mit generierten cp_-IDs (Original unverändert); ALLES in EINER transact=1 Undo-Schritt (Multi-Element undo getestet!); tsc-Fixes: Importpfad 3 Ebenen + CADElement-Type import; Testkorrektur: eigener Rechenfehler in Assertion (Δ20 nicht 30) — Tools korrekt; core-modify v1.2.0 tools:[select,hatch,move,copy]; 3 Tests (move multi+undo, copy neue IDs+undo, auto-select Komfort) | ALLE GRÜN: 448/448 gesamt, tsc 0 | ca1c3c0 | Nächster Task: A4.7 (rotate/scale/mirror/dele ausgleiche Muster) |
+| 2026-08-27 | A4.7 | makeTransformTool-Fabrik NEU: rotate/scale/mirror wirken wie move auf SELEKTION, Legacy-Mathe exakt portiert (rotate: Pivot=ErstesElement-Zentrum+angleBetween-Delta CCW Grad; scale: Faktor=dist(pivot,zweit)/dist(pivot,basis); mirror: Achse basis→referenz); Commit im ZWEITEN down (klick-progressiv, Arc-Lektion angewandt), move-Handler zeigt Live-Vorschau am ersten Element; Zwischenfall REPARATUR: versehentliches Ersetzen der move/copy-Exports beim Einfügen — Datei komplett neu geschrieben statt Flicken-auf-Flicken (alle 7 Tools intakt); updateElement übernimmt transformierte Top-Level-Felder+properties shallow; core-modify v1.3.0 tools:[select,hatch,move,copy,rotate,scale,mirror], rotate/scale/mirror tags:['pro']; 3 Tests (rotate undo, scale Faktor 2 BBox×2, mirror hinter Achse+undo); NOTE-DIESER-EINTRAG-wurde-nachträglich-wiederhergestellt-nach-Patchfehler | ALLE GRÜN: 451/451 gesamt, tsc 0 | 1d598da | Nächster Task: A4.8 (delete+offset) |
+| 2026-08-27 | A4.8 | deleteTool (Selektion→deleteElements in EINER Transaktion; sonst Direktklick-Treffer wie Legacy) + offsetTool in core-modify v1.4.0 (Klick1=Quelle via hitTest, Klick2=Distanz+Seite via Kreuzprodukt bzw. Radius-Vergleich — nutzt BUG-3-reparierte offsetElement(dist,side); erzeugt NEUES Element off_* — Original bleibt); require()-Antipattern durch Top-Level-Import ersetzt; Plugin tools:[...7,delete,offset]; 4 Tests (Multi-delete+undo, Direktklick, Offset-Seite+Konventionen+undo) | ALLE GRÜN: 454/454 gesamt, tsc 0 | cf67635 | Nächster Task: A4.9 (Event-Domain) |
+| 2026-08-27 | A4.9 | event-tools V2 Plugin NEU: chair/seating-row/seating-block/table/stage als Einzelklick-Platzierer über makePlaceTool-Fabrik (placer→CADelement[] normalisiert); Multi-Element-Sätze (Block/Reihe) in EINER transact = 1 Undo entfernt GANZEN Block; BUG-1-Regressionsschutz getestet (rowIds≥3 im Block); Registrierung parallel zum Legacy eventToolsPlugin (koexistiert harmlos — V2-Registry getrenntes Segment); Importpfad sauber über services/seatingService; 3 Tests | ALLE GRÜN: 457/457 gesamt, tsc 0 | 76f305f | Nächster Task: A4.10 (trim/extend/fillet Geometrie-Werkzeuge) |
+| 2026-08-27 | A4.10 | trimTool/extendTool/filletTool in core-modify v1.5.0 via make2PickGeometryTool-Fabrik (trim/extend: Klick1=Kante+Klick2=Ziel; fillet: zwei Picks → Paar-Commit; alle mit doc.updateElement=EINE Transaktion); **FUNKTIONALER GEWINN**: extendElement Fallback lineCircleIntersectionsInfinite (t∈ℝ) implementiert — Legacy extendElement scheiterte still wenn Ziel Kante NICHT berührte, jetzt echtes CAD-Extend (nahe Ende reckt exakt auf Schnittpunkt); Trim-Assertion nach Probe korrigiert (findIntersection wählt NÄCHSTEN Schnitt zu p1 → x=60 nicht 140); Probe-Test-Datei temporär + sauber entfernt; core-modify tools jetzt 12 | ALLE GRÜN: 459/459 gesamt (32 Pilot), tsc 0 | 19f838f | **Werkzeug-Migration 100% COMPLETE** — alle 22 Legacy-Tools existieren als V2-Plugins; Rest-A4: Ribbon-Dynamik, HistoryPanel-Switch, Legacy-Entsorgung (visuell verify nötig) |
+| 2026-08-27 | A4.11 | documentService Singleton NEU (kernel/document/): setActiveDocument/getActiveDocument/onActiveDocumentChanged/undoActive/redoActive — App-Level-Zugriff ohne prop-threading durch God-Component; CanvasArea registriert v2Doc beim Mount (Flag-Pfad) + setActiveDocument(null) im Cleanup; globale Ctrl+Z / Ctrl+Y / Ctrl+Shift+Z Shortcuts nur wirksam bei registriertem V2-Dokument (Legacy-Pfad unangetastet); 3 Tests (Register/Clear, Undo/Redo-Delegation, false ohne Doc) | ALLE GRÜN: 462/462 gesamt, tsc 0, build OK | 25e721d | Nächster Task: A4.12 (V2HistoryPanel) |
+| 2026-08-27 | A4.12 | V2HistoryPanel Komponente NEU: liest UndoManager-Stacks über documentService (registrierte Instanz + einfacher Poll bis A5-Hook), zeigt Einträge neueste zuerst mit 'aktuell'-Markierung; Klick auf aktiven Schritt = undoUntilSlot (mehrfaches doc.undo bis Ziellänge, guard 500); Redo-Einträge rein informativ (Yjs hat keinen nativen jump); Undo/Redo-Buttons oben; App.tsx rendert Flag-abhängig V2HistoryPanel statt Legacy-HistoryPanel (Legacy unverändert); Bezeichnung bewusst generisch 'Schritt N' — Y.Transaction-Labels technisch nicht trivial lesbar, Detail-Label späteres Enhancement | ALLE GRÜN: 462/462 gesamt, tsc 0, build OK | 216bf63 | Nächster Task: A4.13 (Ribbon-Dynamik) |
+| 2026-08-27 | A4.13 | RibbonBar um dynamische V2-Sektion erweitert: im 'canvas'-Tab (nur bei Flag VITE_TOOL_DISPATCHER=v2) rendert Sektion Buttons aus pluginRegistry.getToolsV2() mit icon+label+activeHighlight; Klick feuert onAction('v2tool:<id>'); neues optionales Prop onIsV2ToolActive für Highlight-Zustand (types/ui.types erweitert); App.tsx handleRibbonAction um v2tool:-Zweig erweitert → setActiveTool(toolId) greift den bestehenden A4.1-Sync-Kanal; KEINE Signaturbrüche, volle Abwärtskompatibilität | ALLE GRÜN: 462/462 gesamt, tsc 0, build OK | e370552 | **Phase A abgeschlossen** — Rest (Legacy-Entsorgung) benötigt visuelle Verifikation; Übergabe an Phase C vorbereitet |
+| 2026-08-27 | VERIF | **Korrektur eigener Annahme**: Playwright 1.62 + Chromium waren im Container verfügbar — visuelle Verifikation war automatisierbar; Backend+Frontend als Hintergrundprozesse gestartet; phase-a-verify.test.ts NEU; erster Lauf rot (Textmatching scheiterte an zusammengesetztem textContent) → data-v2tool Attribut eingeführt, Test auf Attribut-Selektor umgestellt; LAUF GRÜN: V2-Sektion sichtbar, 22 Buttons, Linie aktiviert, Zug+Undo/Redo crashfrei ohne pageerror/v2-console-error; Screenshots erzeugt | PLAYWRIGHT GRUEN | — | Übergabepunkt geschlossen: Legacy-Entsorgung freigegeben |
+| 2026-08-27 | A4.14 | FLAG-INVERTIERUNG: kernel/featureFlags.ts NEU (V2_TOOLS_ENABLED zentral), alle 4 Flag-Stellen umgestellt (CanvasArea-Dispatcher-Block, App-HistoryPanel, App-onIsV2ToolActive, RibbonBar-Sektion); Opt-out via VITE_TOOL_DISPATCHER=legacy statt Opt-in; BEWEIS: Dev-Server OHNE Flag neu gestartet, phase-a-verify GRUEN (V2-Sektion sichtbar + Zeichnen + Undo/Redo crashfrei); verwaiste Prozesse per pkill beendet | ALLE GRUEN: 462/462 gesamt, tsc 0, build OK, E2E OHNE Flag gruen | 69141d6 | **PHASE A ABGESCHLOSSEN** · Legacy-Pfad bleibt als dokumentiertes Opt-out erhalten; nächstes: Phase C (PixiJS/WebGL) oder Phase-D-Extensions |
+| 2026-08-27 | C1 | render/types.ts NEU mit RenderAdapter-Interface (init/resize/setViewport/destroy/clear/drawGrid/drawBackground/drawRuler/drawElement/drawPreview/setSelection/setSnapPoints/overlay/hitTest) + Hilfstypen Viewport/GridConfig/BackgroundDrawConfig/RulerConfig/LayerStyle/OverlayPainter/SelectionState; render/mock/MockAdapter.ts als headless Recorder; CADLayer-Fix nach selbsterkanntem never-Workaround; 4 Smoke-Tests inkl. Compile-proof; pixi.js@8.20.1 vorinstalliert | ALLE GRUEN: 466/466 gesamt (+4), tsc 0 | c962e75 | Naechster Task: C2 (PixiJS-Grundgeruest) |
+| 2026-08-27 | C2 | PixiRenderer NEU: async Application.init() mit waitForReady()-Promise; inkrementelles Rendering via Map<elementId, Container> (drawElement remove/rebuild statt Full-Redraw); clearElements fuer Dokumentwechsel; drawPreview mit __preview__-Label + Alpha 0.6; drawGrid skaliert im Welt-Layer; overlay() mit OverlayPainter-API; hitTest Stub (SpatialIndex-Delegation C3); tsc bestaetigt Pixi v8 API; Build gruen = Bundle-safe | ALLE GRUEN: 475/475 gesamt (+9 elementDrawers), tsc 0, build OK | dde5077 | Naechster Task: C3 oder Renderer-Integration hinter Flag |
+| 2026-08-27 | C2int | PixiRenderer in CanvasArea integriert: pixiCanvasRef+pixiRendererRef, Overlay-Canvas (position absolute, zIndex 5, pointerEvents none) ueber Legacy-Canvas, PixiRenderer-Instanziierung im Flag-Block, syncPixi mit REFERENZDIFF (lastKnownEl Map, kein JSON.stringify) + Cleanup-Delete fehlender IDs, pixi.destroy im Cleanup; **KRITISCHER BUG GEFUNDEN UND GEFIXT**: statischer pixi.js-Import im Modul-Load crashte die gesamte React-App (weisser Screen, keine Canvas gemountet) — Loesung: LAZY-IMPORT via dynamic import() in PixiRenderer.init, Modul-Fehler bleiben auf Overlay beschraenkt, App laeuft weiter; defensives try/catch + waitForReady().catch als doppelte Absicherung; BEWEIS: Playwright phase-a-verify GRUEN nach Fix (5.7s) mit vollem Zeichnen+Undo-Flow; alle 22 Tools zeichnen jetzt UEBER PixiJS auf das Overlay | ALLE GRUEN: 475/475 gesamt, tsc 0, build OK, E2E gruen | 8b1cca0 | C2 complete; naechster: C3 (Atlas/Dimensionen/Selection) oder C4 (Flag-Umdrehung Pixi=Default) |
+| 2026-08-27 | C3fin | Selection-Handles + Snap-Marks im PixiRenderer: setSelection zeichnet pro selektiertem Element gestrichelte BBox-Umrandung + 4 Eck-Handles (gruen, skalenkompensiert); SelectionState um elements? erweitert (Renderer braucht BBox-Zugriff); setSnapPoints farbige Kreise nach Typ (endpoint/midpoint/center/intersection/grid), skalenkompensiert;__selection__/__snaps__-Labels fuer Cleanup; tsc+481 Tests+Build GRUEN | siehe git | C3-FINISH complete |
+| 2026-08-27 | C4 | USE_PIXI_RENDERER Flag (Opt-out via VITE_USE_PIXI=false); PixiRenderer um initialized-Flag + getDebugInfo() erweitert; CanvasArea um USE_PIXI_RENDERER gebunden + window.__v2Debug-Hook nach waitForReady; Playwright-Spec um Pixi-Assertions erweitert (cachedElements >=1 nach Zeichnen, =0 nach Undo, ready=true); E2E GRUEN 7.5s | ALLE GRUEN: 481/481 gesamt, tsc 0, build OK, E2E mit Pixi-Assertions gruen | siehe git | C4 COMPLETE — Pixi ist jetzt Standard-Renderer fuer V2-Elemente |
+| 2026-08-27 | C3fin2 | Snap-Marks + Selection-Handles an CanvasArea-Events gebunden: pointermove-Listener ruft snapEngine.snap + pixi.setSnapPoints (nur bei aktivem V2-Tool); selectionEngine.selectByIds gewrapt um pixi.setSelection mit Elementen aufzurufen; tsc+481 Tests+Build GRUEN | siehe git 042c546 | C3fin-INTEGRATION complete |
+| 2026-08-27 | D-ext | array-rect/array-polar in core-modify v1.6.0: makeArrayTool-Fabrik, wirken auf Selektion (Klick1=Basis+Auto-HitSelect, Klick2=Commit); rect: rows/cols/dx/dy aus Options-Schema; polar: count aus Options, rotiert Elementposition um Basis; ALLES in EINER transact=1 Undo-Schritt; 2 Tests (rect 2x2=4 Elemente+undo, polar count=4+undo); core-modify tools jetzt 14 | ALLE GRUEN: 483/483 gesamt (+2), tsc 0, build OK | d5b6395 | D-ARRAY COMPLETE; weitere D-Extensions (chamfer, grip, etc.) folgen |
+| 2026-08-27 | D-ext3 | join/explode/align in core-modify v1.8.0: join=Selektions-Linien→Polyline (Punkte gesammelt), explode=Polyline→Einzelsegmente (Original entfernt), align=Element auf Ziel-Position verschieben; alle via doc.transact=undo-faehig; core-modify tools jetzt 19 | ALLE GRUEN: 485/485 gesamt, tsc 0, build OK | b470ac3 | D-EXT3 COMPLETE |
+| 2026-08-27 | D-fin | polyline-edit + stretch + break in core-modify v1.9.0: polyline-edit (Vertex ziehen mit Preview + doc.updateElement), stretch (Endpunkte in Basisnähe verschieben), break (Linie am Klickpunkt teilen — Original entfernt, 2 neue hinzugefuegt); core-modify tools jetzt 22 | ALLE GRUEN: 485/485 gesamt, tsc 0, build OK | 5500462 | **PHASE D COMPLETE** — core-modify deckt vollstaendigen CAD-Standardumfang ab |
+| 2026-08-27 | E1 | seating-row + seating-block auf Drag-Interaktion umgestellt (Klick1=Start, Drag=Preview, up=Commit); spacing/colSpacing/rowSpacing aus Options-Schema; count aus Distanz berechnet; A4.9-Tests an Drag-Verhalten angepasst; 4 neue Tests (row Laenge+undo, row cancel, block rows×cols+undo, BUG-1-Regression) | ALLE GRUEN: 488/488 gesamt (+3), tsc 0, build OK | siehe git | E1 COMPLETE |
+| 2026-08-27 | E2 | createArcRow in SeatingService + arcRowTool in event-tools: 3-Klick-Sequenz (Zentrum→Radius→Endwinkel), Stuehle tangential rotiert (angle+90), spacing aus Options, rowId unique; klick-progressiv wie Arc-Lektion | ALLE GRUEN: 488/488 gesamt, tsc 0, build OK | siehe git | E2 COMPLETE |
+| 2026-08-27 | E3 | seatCount in StatusBar bereits vorhanden (App.tsx L193 useMemo + StatusBar Prop) — E3 SKIP (schon da) | — | — | E3 SKIP |
+| 2026-08-27 | E4 | Vorlagenkatalog: kino (5×15 Reihen), bankett-rundtisch (180cm Tisch + 8 Stühle), stehtisch (80cm + 5 Stühle), podest (300×200 Bühne) als makePlaceTool-Klick-Platzierer; event-tools tools jetzt 10 | ALLE GRUEN: 488/488 gesamt, tsc 0, build OK | 214e57c | E4 COMPLETE |
+| 2026-08-28 | E5 | exportSeatListCSV in SeatingService (Header + chair-Zeilen mit rowId/blockId/x/y); 3 Tests (CSV-Struktur, Nicht-Stuhl ignoriert, leer→nur Header) | ALLE GRUEN: 491/491 gesamt (+3), tsc 0 | 6a214c2 | E5 COMPLETE |
+| 2026-08-28 | E6-backend | Gäste-CRUD: guests-Tabelle in schema.sql (drawing_id FK CASCADE + Index), DBGuest-Interface, SqliteAdapter (list/get/create/update/delete), routes/guests.ts (GET/POST /api/drawings/:id/guests, PATCH/DELETE /api/guests/:id, requireAuth + Validation), server.ts-Registrierung | Backend: 255/255 Tests, tsc 0 | e99cf59 | E6-BACKEND COMPLETE |
+| 2026-08-28 | E6-frontend | GuestPanel-Komponente (Liste+Suche+Hinzufügen+Löschen+Zuweisungsanzeige), Guest-API in api.ts (list/create/update/deleteGuest), App.tsx-Integration (guestPanelOpen-State, guests-Action, Overlay-Render mit drawingId-Guard), RibbonBar-Button „Gäste" in Extras-Gruppe | Frontend: 491/491 Tests, tsc 0, build OK | 5eb741d | E6 COMPLETE — Gäste-Verwaltung funktional (Stuhl-Klick-Zuweisung folgt in E6b) |
+| 2026-08-28 | E6b | Stuhl-Zuweisung per Canvas-Auswahl: __v2GetSelection-Bridge in CanvasArea (liefert selectionEngine.getSelectedIds), GuestPanel 💺-Button pro Gast (erste Canvas-Auswahl → seat_element_id via updateGuest; Klick auf zugewiesenen Gast hebt Zuweisung auf) | ALLE GRUEN: 491/491 gesamt, tsc 0, build OK | 626d565 | **E6b COMPLETE — Gäste-Verwaltung Ende-zu-Ende funktional**: Stuhl im Canvas wählen → 💺 → Gast sitzt dort |
+| 2026-08-28 | F1-backend | .wcadlib Export/Import: GET /api/global-blocks/export (folders+blocks JSON-Paket), POST /api/global-blocks/import (ID-Mapping für Ordner-Hierarchie, Validierung format=wcadlib); 3 Tests (Export-Struktur, Import mit Mapping, falsches Format→400); **BONUS-BUGFIX**: gblock-/gfolder-ID-Kollision (Date.now ohne Suffix, gleiche Bug-Klasse wie BUG-1) → randomUUID-Slice | Backend: 258/258 Tests (+3), tsc 0 | 5cbfe55 | F1-BACKEND COMPLETE; 5 weitere Date.now()-IDs (user/proj/pfolder/draw/layer/block) als Nebenproblem notiert |
+| 2026-08-28 | F1-frontend | BlockLibraryTree: Export-Button (lädt .wcadlib herunter) + Import-Button (.wcadlib-File-Input → importLibrary → loadData-Refresh) + API-Funktionen exportLibrary/importLibrary in api.ts | Frontend: 491/491 Tests, tsc 0, build OK | 63c8968 | **F1 COMPLETE — Library Export/Import Ende-zu-Ende**: Bibliothek als .wcadlib-Paket teilen/archivieren/einspielen |
+| 2026-08-27 | C3 | elementToPrimitives erweitert um fehlende Typen: dimension (Linie + Label aus value/text), leader (Linie + Label am Ende), revcloud (geschlossener Punktzug), chair (gefuelltes Rechteck #4a90d9), table (Kreis #8b7355), stage (dunkles Rechteck #3a3a4a); Legacy-Konventionen beibehalten; 6 neue Tests | ALLE GRUEN: 481/481 gesamt (+6), tsc 0, build OK | siehe git | Naechster Task: C4 (Flag-Umdrehung Pixi=Default) oder Selection-Handles/Snap-Marks |
+| 2026-08-28 | F2-backend | Block-Favoriten: schema.sql is_favorite INTEGER DEFAULT 0 + SqliteAdapter-Migration (PRAGMA table_info-Muster) für Bestands-DBs, mapGlobalBlockRow 0/1→boolean, createGlobalBlock/updateGlobalBlock erweitert, DBGlobalBlock.is_favorite: boolean, PATCH /api/global-blocks/:id validiert is_favorite (nicht-boolean→400); ROT-Beweis: 5 Tests zuerst ROT (is_favorite fehlte komplett), dann GRUEN | Backend: 263/263 Tests (+5), tsc 0 | 83a94e4 | F2-BACKEND COMPLETE |
+| 2026-08-28 | F2-frontend | BlockLibraryTree: Suchfeld (global-lib-toolbar, filtert root+folder+favorites), ★/☆-Favorite-Toggle je Block (setGlobalBlockFavorite-API, optimistisches UI-Update), Favoriten-Sektion mit goldenem Titel, SVG-Thumbnail-Vorschau (tree-thumb, dangerouslySetInnerHTML, Fallback 📦), Grid-Ansicht (lib-grid, Thumbnail-Zellen mit Drag-Drop + Kontextmenü + Favorit); GlobalBlock.is_favorite: boolean in api.ts | Frontend: 491/491 Tests, tsc 0, build OK | 8b50c0a | **F2 COMPLETE — LibraryPanel-Kernfeatures**: Baum+Suche+Favoriten+Thumbnails+Grid+DragDrop→Canvas (Drop-Handler existierte bereits) |
+| 2026-08-28 | F3 | blockThumbnail.ts NEU (generateBlockSvg/primitivesToSvg: Elemente→elementToPrimitives→eigenständiges SVG mit PAD-BBox, alle 6 Primitive-Kinds, XML-Escape, Arc→path mit Konvention 0°=3Uhr/CCW); Save-Button 💾 im Bibliotheks-Header (liest __v2GetSelection + documentService.getActiveDocument, Name via prompt, block_data=Element-Array → Drop-Handler akzeptiert Arrays, svg_data=Thumbnail, createGlobalBlock+loadData-Refresh); Dokumentierte Abweichung: SVG statt canvas.toDataURL (konsistent, testbar); ROT-Beweis: 4 Tests zuerst fehlgeschlagen (Modul fehlte), 1 Erwartung nach Primitive-BBox-Analyse korrigiert (-50 -50 560 360); Fix: Duplikat-Import + Handler vor loadData-Deklaration (tsc 2300/2448) | Frontend: 495/495 Tests (+4), tsc 0, build OK | 5d8253a | **F3 COMPLETE — Auswahl als Block speichern**: Canvas-Selektion → wiederverwendbarer Block mit Thumbnail, sofort per DragDrop einsetzbar |
+| 2026-08-28 | ids | Nebenproblem „Date.now()-IDs“ erledigt: Alle 9 verbleibenden Auto-ID-Generierungen im SqliteAdapter (user/proj/pfolder/draw/layer/elem/block/notif/share) auf etabliertes randomUUID().slice(0,8)-Muster umgestellt (gleiche BUG-1-Kollisionsklasse wie gblock-Fix in F1); Deterministischer ROT-Beweis: 4 neue Tests mit vi.useFakeTimers+EINGEFRORENER Systemzeit (zwei Creates im selben Tick → UNIQUE-PK-Exception mit Date.now, eindeutig mit UUID); perl-Escape-Fehler (\${p} literal) selbst erkannt und zeilenweise korrigiert | Backend: 267/267 Tests (+4), tsc 0 | c78d8d8 | **BUG-1-KLASSE GESCHLOSSEN** — keine Date.now()-Auto-IDs mehr im Backend |
+
+## Gefundene Nebenprobleme (noch nicht zugewiesen)
+- `webhook-receiver.py` im Root: Zweck unklar, ggf. entfernen/dokumentieren (Frage an Nutzer)
+- `phase2..4-task-spec.md` veraltet gegenüber BAUPLAN — nach v2.0 archivieren
+- `frontend/src/utils/__tests__/format.test.ts` liegt in src statt tests/ — vereinheitlichen (kleiner Task in I2)
+
+---
+*Nächster offener Schritt: **I3** (Release 2.0: Tag + Docker-Images + Coolify-Deploy-Verify) — der LETZTE offene Roadmap-Punkt. Alle Phasen A–H + I1 + I2 sind komplett.*
+*Status 2026-08-29: ALLE FUNKTIONALEN PHASEN B+C+D+E+F+G+H VOLLSTÄNDIG, I1 CI + I2 Docs fertig. FE 697/697 Tests, BE 287/287, tsc/Build grün. Alle Commits auf Forgejo main. Offen: NUR NOCH I3 (Release 2.0).*

backend/package-lock.json

@@ -14,6 +14,7 @@
         "bcrypt": "^6.0.0",
         "better-sqlite3": "^11.0.0",
         "fastify": "^5.9.0",
+        "jszip": "^3.10.1",
         "y-leveldb": "^0.2.0",
         "y-protocols": "^1.0.7",
         "yjs": "^13.6.0"
@@ -1503,6 +1504,11 @@
         "url": "https://opencollective.com/express"
       }
     },
+    "node_modules/core-util-is": {
+      "version": "1.0.3",
+      "resolved": "https://registry.npmjs.org/core-util-is/-/core-util-is-1.0.3.tgz",
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+    },
     "node_modules/decompress-response": {
       "version": "6.0.0",
       "resolved": "https://registry.npmjs.org/decompress-response/-/decompress-response-6.0.0.tgz",
@@ -1886,6 +1892,11 @@
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       ]
     },
+    "node_modules/immediate": {
+      "version": "3.0.6",
+      "resolved": "https://registry.npmjs.org/immediate/-/immediate-3.0.6.tgz",
+      "integrity": "sha512-XXOFtyqDjNDAQxVfYxuF7g9Il/IbWmmlQg2MYKOH8ExIT1qg6xc4zyS3HaEEATgs1btfzxq15ciUiY7gjSXRGQ=="
+    },
     "node_modules/inherits": {
       "version": "2.0.4",
       "resolved": "https://registry.npmjs.org/inherits/-/inherits-2.0.4.tgz",
@@ -1926,6 +1937,11 @@
         "node": ">=4"
       }
     },
+    "node_modules/isarray": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/isarray/-/isarray-1.0.0.tgz",
+      "integrity": "sha512-VLghIWNM6ELQzo7zwmcg0NmTVyWKYjvIeM83yjp0wRDTmUnrM678fQbcKBo6n2CJEF0szoG//ytg+TKla89ALQ=="
+    },
     "node_modules/isomorphic.js": {
       "version": "0.2.5",
       "resolved": "https://registry.npmjs.org/isomorphic.js/-/isomorphic.js-0.2.5.tgz",
@@ -1958,6 +1974,44 @@
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     },
+    "node_modules/jszip": {
+      "version": "3.10.1",
+      "resolved": "https://registry.npmjs.org/jszip/-/jszip-3.10.1.tgz",
+      "integrity": "sha512-xXDvecyTpGLrqFrvkrUSoxxfJI5AH7U8zxxtVclpsUtMCq4JQ290LY8AW5c7Ggnr/Y/oK+bQMbqK2qmtk3pN4g==",
+      "dependencies": {
+        "lie": "~3.3.0",
+        "pako": "~1.0.2",
+        "readable-stream": "~2.3.6",
+        "setimmediate": "^1.0.5"
+      }
+    },
+    "node_modules/jszip/node_modules/readable-stream": {
+      "version": "2.3.8",
+      "resolved": "https://registry.npmjs.org/readable-stream/-/readable-stream-2.3.8.tgz",
+      "integrity": "sha512-8p0AUk4XODgIewSi0l8Epjs+EVnWiK7NoDIEGU0HhE7+ZyY8D1IMY7odu5lRrFXGg71L15KG8QrPmum45RTtdA==",
+      "dependencies": {
+        "core-util-is": "~1.0.0",
+        "inherits": "~2.0.3",
+        "isarray": "~1.0.0",
+        "process-nextick-args": "~2.0.0",
+        "safe-buffer": "~5.1.1",
+        "string_decoder": "~1.1.1",
+        "util-deprecate": "~1.0.1"
+      }
+    },
+    "node_modules/jszip/node_modules/safe-buffer": {
+      "version": "5.1.2",
+      "resolved": "https://registry.npmjs.org/safe-buffer/-/safe-buffer-5.1.2.tgz",
+      "integrity": "sha512-Gd2UZBJDkXlY7GbJxfsE8/nvKkUEU1G38c1siN6QP6a9PT9MmHB8GnpscSmMJSoF8LOIrt8ud/wPtojys4G6+g=="
+    },
+    "node_modules/jszip/node_modules/string_decoder": {
+      "version": "1.1.1",
+      "resolved": "https://registry.npmjs.org/string_decoder/-/string_decoder-1.1.1.tgz",
+      "integrity": "sha512-n/ShnvDi6FHbbVfviro+WojiFzv+s8MPMHBczVePfUpDJLwoLT0ht1l4YwBCbi8pJAveEEdnkHyPyTP/mzRfwg==",
+      "dependencies": {
+        "safe-buffer": "~5.1.0"
+      }
+    },
     "node_modules/level": {
       "version": "8.0.1",
       "resolved": "https://registry.npmjs.org/level/-/level-8.0.1.tgz",
@@ -2135,6 +2189,14 @@
         "url": "https://github.com/sponsors/dmonad"
       }
     },
+    "node_modules/lie": {
+      "version": "3.3.0",
+      "resolved": "https://registry.npmjs.org/lie/-/lie-3.3.0.tgz",
+      "integrity": "sha512-UaiMJzeWRlEujzAuw5LokY1L5ecNQYZKfmyZ9L7wDHb/p5etKaxXhohBcrw0EYby+G/NA52vRSN4N39dxHAIwQ==",
+      "dependencies": {
+        "immediate": "~3.0.5"
+      }
+    },
     "node_modules/light-my-request": {
       "version": "6.6.0",
       "resolved": "https://registry.npmjs.org/light-my-request/-/light-my-request-6.6.0.tgz",
@@ -2587,6 +2649,11 @@
         "wrappy": "1"
       }
     },
+    "node_modules/pako": {
+      "version": "1.0.11",
+      "resolved": "https://registry.npmjs.org/pako/-/pako-1.0.11.tgz",
+      "integrity": "sha512-4hLB8Py4zZce5s4yd9XzopqwVv/yGNhV1Bl8NTmCq1763HeK2+EwVTv+leGeL13Dnh2wfbqowVPXCIO0z4taYw=="
+    },
     "node_modules/path-scurry": {
       "version": "2.0.2",
       "resolved": "https://registry.npmjs.org/path-scurry/-/path-scurry-2.0.2.tgz",
@@ -2722,6 +2789,11 @@
         "node": ">= 0.6.0"
       }
     },
+    "node_modules/process-nextick-args": {
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/process-nextick-args/-/process-nextick-args-2.0.1.tgz",
+      "integrity": "sha512-3ouUOpQhtgrbOa17J7+uxOTpITYWaGP7/AhoR3+A+/1e9skrzelGi/dXzEYyvbxubEF6Wn2ypscTKiKJFFn1ag=="
+    },
     "node_modules/process-warning": {
       "version": "5.0.0",
       "resolved": "https://registry.npmjs.org/process-warning/-/process-warning-5.0.0.tgz",
@@ -2969,6 +3041,11 @@
       "resolved": "https://registry.npmjs.org/set-cookie-parser/-/set-cookie-parser-2.7.2.tgz",
       "integrity": "sha512-oeM1lpU/UvhTxw+g3cIfxXHyJRc/uidd3yK1P242gzHds0udQBYzs3y8j4gCCW+ZJ7ad0yctld8RYO+bdurlvw=="
     },
+    "node_modules/setimmediate": {
+      "version": "1.0.5",
+      "resolved": "https://registry.npmjs.org/setimmediate/-/setimmediate-1.0.5.tgz",
+      "integrity": "sha512-MATJdZp8sLqDl/68LfQmbP8zKPLQNV6BIZoIgrscFDQ+RsvK/BxeDQOgyxKKoh0y/8h3BqVFnCqQ/gd+reiIXA=="
+    },
     "node_modules/setprototypeof": {
       "version": "1.2.0",
       "resolved": "https://registry.npmjs.org/setprototypeof/-/setprototypeof-1.2.0.tgz",

backend/package.json

@@ -18,6 +18,7 @@
     "bcrypt": "^6.0.0",
     "better-sqlite3": "^11.0.0",
     "fastify": "^5.9.0",
+    "jszip": "^3.10.1",
     "y-leveldb": "^0.2.0",
     "y-protocols": "^1.0.7",
     "yjs": "^13.6.0"

backend/src/auth/authMiddleware.ts

@@ -44,3 +44,20 @@ export function requireAdmin(request: FastifyRequest, reply: FastifyReply, authS
   }
   return user;
 }
+
+/**
+ * Require library-admin role (Task H3: global library write guard).
+ * Library-admin is bound to the existing admin role: only admins may
+ * write (create/update/delete/import) the GLOBAL block library, while
+ * every authenticated user may read/export it. Own drawing-scoped
+ * blocks are unaffected (per-user ownership there).
+ */
+export function requireLibraryAdmin(request: FastifyRequest, reply: FastifyReply, authService: AuthService): DBUser | null {
+  const user = requireAuth(request, reply, authService);
+  if (!user) return null;
+  if (user.role !== 'admin') {
+    reply.code(403).send({ error: 'Library admin access required' });
+    return null;
+  }
+  return user;
+}

backend/src/database/DatabaseInterface.ts

@@ -121,6 +121,7 @@ export interface DBGlobalBlock {
   name: string;
   block_data: string;
   svg_data: string | null;
+  is_favorite: boolean;
   created_at: string;
   updated_at: string;
 }
@@ -213,4 +214,23 @@ export interface DatabaseInterface {
   createGlobalBlock(data: Partial<DBGlobalBlock>): DBGlobalBlock;
   updateGlobalBlock(id: string, data: Partial<DBGlobalBlock>): DBGlobalBlock | null;
   deleteGlobalBlock(id: string): boolean;
+
+  // Guests (Task E6)
+  listGuests(drawingId: string): DBGuest[];
+  getGuest(id: string): DBGuest | null;
+  createGuest(data: Partial<DBGuest>): DBGuest;
+  updateGuest(id: string, data: Partial<DBGuest>): DBGuest | null;
+  deleteGuest(id: string): boolean;
+}
+
+// ─── Guests (Task E6) ──────────────────────────────────
+export interface DBGuest {
+  id: string;
+  drawing_id: string;
+  name: string;
+  email?: string;
+  category: string; // 'standard' | 'vip' | 'staff'
+  seat_element_id?: string;  // Verknüpfung zu einem chair-Element
+  notes?: string;
+  created_at: string;
 }

backend/src/database/SqliteAdapter.ts

@@ -11,6 +11,7 @@ import type {
   DBElement, DBBlock, DBSetting, DBUser, DBSession,
   DBNotification, DBProjectShare,
   DBGlobalBlockFolder, DBGlobalBlock,
+  DBGuest,
   DBProjectFolder,
 } from './DatabaseInterface.js';
 
@@ -34,6 +35,11 @@ export class SqliteAdapter implements DatabaseInterface {
     if (!columns.some(col => col.name === 'folder_id')) {
       this.db.exec('ALTER TABLE projects ADD COLUMN folder_id TEXT REFERENCES project_folders(id) ON DELETE SET NULL');
     }
+    // Add is_favorite column to global_blocks table for existing databases (Task F2)
+    const gbColumns = this.db.prepare("PRAGMA table_info('global_blocks')").all() as { name: string }[];
+    if (!gbColumns.some(col => col.name === 'is_favorite')) {
+      this.db.exec('ALTER TABLE global_blocks ADD COLUMN is_favorite INTEGER NOT NULL DEFAULT 0');
+    }
   }
 
   close(): void {
@@ -50,7 +56,7 @@ export class SqliteAdapter implements DatabaseInterface {
   }
 
   createUser(data: Partial<DBUser>): DBUser {
-    const id = data.id ?? `user-${Date.now()}`;
+    const id = data.id ?? `user-${randomUUID().slice(0, 8)}`;
     this.db.prepare(
       'INSERT INTO users (id, email, password_hash, name, role) VALUES (?, ?, ?, ?, ?)',
     ).run(id, data.email!, data.password_hash!, data.name!, data.role ?? 'planer');
@@ -104,7 +110,7 @@ export class SqliteAdapter implements DatabaseInterface {
   }
 
   createProject(data: Partial<DBProject>): DBProject {
-    const id = data.id ?? `proj-${Date.now()}`;
+    const id = data.id ?? `proj-${randomUUID().slice(0, 8)}`;
     this.db.prepare(
       'INSERT INTO projects (id, name, description, owner_id, folder_id) VALUES (?, ?, ?, ?, ?)',
     ).run(id, data.name ?? 'Unbenannt', data.description ?? null, data.owner_id ?? 'user-default', data.folder_id ?? null);
@@ -143,7 +149,7 @@ export class SqliteAdapter implements DatabaseInterface {
   }
 
   createProjectFolder(data: Partial<DBProjectFolder>): DBProjectFolder {
-    const id = data.id ?? `pfolder-${Date.now()}`;
+    const id = data.id ?? `pfolder-${randomUUID().slice(0, 8)}`;
     this.db.prepare(
       'INSERT INTO project_folders (id, name, parent_id, owner_id) VALUES (?, ?, ?, ?)',
     ).run(id, data.name ?? 'Neuer Ordner', data.parent_id ?? null, data.owner_id ?? 'user-default');
@@ -177,7 +183,7 @@ export class SqliteAdapter implements DatabaseInterface {
   }
 
   createDrawing(data: Partial<DBDrawing>): DBDrawing {
-    const id = data.id ?? `draw-${Date.now()}`;
+    const id = data.id ?? `draw-${randomUUID().slice(0, 8)}`;
     this.db.prepare(
       'INSERT INTO drawings (id, project_id, name, data_json) VALUES (?, ?, ?, ?)',
     ).run(id, data.project_id!, data.name ?? 'Unbenannt', data.data_json ?? '{}');
@@ -206,7 +212,7 @@ export class SqliteAdapter implements DatabaseInterface {
   }
 
   createLayer(data: Partial<DBLayer>): DBLayer {
-    const id = data.id ?? `layer-${Date.now()}`;
+    const id = data.id ?? `layer-${randomUUID().slice(0, 8)}`;
     // Idempotent: if a layer with the same id already exists, return it.
     // This prevents race conditions under React StrictMode double-render.
     const existing = this.db.prepare('SELECT * FROM layers WHERE id = ?').get(id) as DBLayer | undefined;
@@ -243,7 +249,7 @@ export class SqliteAdapter implements DatabaseInterface {
   }
 
   createElement(data: Partial<DBElement>): DBElement {
-    const id = data.id ?? `elem-${Date.now()}`;
+    const id = data.id ?? `elem-${randomUUID().slice(0, 8)}`;
     this.db.prepare(
       'INSERT INTO elements (id, drawing_id, layer_id, type, x, y, width, height, properties_json) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)',
     ).run(id, data.drawing_id!, data.layer_id!, data.type!, data.x ?? 0, data.y ?? 0,
@@ -275,7 +281,7 @@ export class SqliteAdapter implements DatabaseInterface {
   }
 
   createBlock(data: Partial<DBBlock>): DBBlock {
-    const id = data.id ?? `block-${Date.now()}`;
+    const id = data.id ?? `block-${randomUUID().slice(0, 8)}`;
     this.db.prepare(
       'INSERT INTO blocks (id, drawing_id, name, description, category, elements_json, thumbnail) VALUES (?, ?, ?, ?, ?, ?, ?)',
     ).run(id, data.drawing_id!, data.name ?? 'Block', data.description ?? null,
@@ -346,7 +352,7 @@ export class SqliteAdapter implements DatabaseInterface {
   }
 
   createNotification(data: Partial<DBNotification>): DBNotification {
-    const id = data.id ?? `notif-${Date.now()}`;
+    const id = data.id ?? `notif-${randomUUID().slice(0, 8)}`;
     this.db.prepare(
       'INSERT INTO notifications (id, user_id, type, title, message, read) VALUES (?, ?, ?, ?, ?, ?)',
     ).run(id, data.user_id!, data.type ?? 'info', data.title!, data.message!, data.read ?? 0);
@@ -371,7 +377,7 @@ export class SqliteAdapter implements DatabaseInterface {
   }
 
   createProjectShare(data: Partial<DBProjectShare>): DBProjectShare {
-    const id = data.id ?? `share-${Date.now()}`;
+    const id = data.id ?? `share-${randomUUID().slice(0, 8)}`;
     const shareToken = data.share_token ?? randomUUID();
     this.db.prepare(
       'INSERT INTO project_shares (id, project_id, shared_with_email, shared_by, permission, share_token) VALUES (?, ?, ?, ?, ?, ?)',
@@ -399,7 +405,7 @@ export class SqliteAdapter implements DatabaseInterface {
   }
 
   createGlobalFolder(data: Partial<DBGlobalBlockFolder>): DBGlobalBlockFolder {
-    const id = data.id ?? `gfolder-${Date.now()}`;
+    const id = data.id ?? `gfolder-${randomUUID().slice(0, 8)}`;
     this.db.prepare(
       'INSERT INTO global_block_folders (id, name, parent_id) VALUES (?, ?, ?)',
     ).run(id, data.name ?? 'Neuer Ordner', data.parent_id ?? null);
@@ -422,25 +428,31 @@ export class SqliteAdapter implements DatabaseInterface {
   }
 
   // ─── Global Blocks ─────────────────────────────────────
+  // Map DB row to DBGlobalBlock (is_favorite 0/1 → boolean, Task F2)
+  private mapGlobalBlockRow(row: Record<string, unknown>): DBGlobalBlock {
+    return { ...(row as unknown as DBGlobalBlock), is_favorite: Number(row.is_favorite ?? 0) === 1 };
+  }
+
   listGlobalBlocks(folderId?: string | null): DBGlobalBlock[] {
     if (folderId === undefined) {
-      return this.db.prepare('SELECT * FROM global_blocks ORDER BY updated_at DESC').all() as DBGlobalBlock[];
+      return (this.db.prepare('SELECT * FROM global_blocks ORDER BY updated_at DESC').all() as Record<string, unknown>[]).map(r => this.mapGlobalBlockRow(r));
     }
     if (folderId === null) {
-      return this.db.prepare('SELECT * FROM global_blocks WHERE folder_id IS NULL ORDER BY updated_at DESC').all() as DBGlobalBlock[];
+      return (this.db.prepare('SELECT * FROM global_blocks WHERE folder_id IS NULL ORDER BY updated_at DESC').all() as Record<string, unknown>[]).map(r => this.mapGlobalBlockRow(r));
     }
-    return this.db.prepare('SELECT * FROM global_blocks WHERE folder_id = ? ORDER BY updated_at DESC').all(folderId) as DBGlobalBlock[];
+    return (this.db.prepare('SELECT * FROM global_blocks WHERE folder_id = ? ORDER BY updated_at DESC').all(folderId) as Record<string, unknown>[]).map(r => this.mapGlobalBlockRow(r));
   }
 
   getGlobalBlock(id: string): DBGlobalBlock | null {
-    return (this.db.prepare('SELECT * FROM global_blocks WHERE id = ?').get(id) as DBGlobalBlock) ?? null;
+    const row = this.db.prepare('SELECT * FROM global_blocks WHERE id = ?').get(id) as Record<string, unknown> | undefined;
+    return row ? this.mapGlobalBlockRow(row) : null;
   }
 
   createGlobalBlock(data: Partial<DBGlobalBlock>): DBGlobalBlock {
-    const id = data.id ?? `gblock-${Date.now()}`;
+    const id = data.id ?? `gblock-${randomUUID().slice(0, 8)}`;
     this.db.prepare(
-      'INSERT INTO global_blocks (id, folder_id, name, block_data, svg_data) VALUES (?, ?, ?, ?, ?)',
-    ).run(id, data.folder_id ?? null, data.name ?? 'Global Block', data.block_data ?? '{}', data.svg_data ?? null);
+      'INSERT INTO global_blocks (id, folder_id, name, block_data, svg_data, is_favorite) VALUES (?, ?, ?, ?, ?, ?)',
+    ).run(id, data.folder_id ?? null, data.name ?? 'Global Block', data.block_data ?? '{}', data.svg_data ?? null, data.is_favorite ? 1 : 0);
     return this.getGlobalBlock(id)!;
   }
 
@@ -451,6 +463,7 @@ export class SqliteAdapter implements DatabaseInterface {
     if (data.folder_id !== undefined) { sets.push('folder_id = ?'); vals.push(data.folder_id); }
     if (data.block_data !== undefined) { sets.push('block_data = ?'); vals.push(data.block_data); }
     if (data.svg_data !== undefined) { sets.push('svg_data = ?'); vals.push(data.svg_data); }
+    if (data.is_favorite !== undefined) { sets.push('is_favorite = ?'); vals.push(data.is_favorite ? 1 : 0); }
     sets.push("updated_at = datetime('now')");
     this.db.prepare(`UPDATE global_blocks SET ${sets.join(', ')} WHERE id = ?`).run(...vals, id);
     return this.getGlobalBlock(id);
@@ -459,4 +472,37 @@ export class SqliteAdapter implements DatabaseInterface {
   deleteGlobalBlock(id: string): boolean {
     return this.db.prepare('DELETE FROM global_blocks WHERE id = ?').run(id).changes > 0;
   }
+
+  // ─── Guests (Task E6) ──────────────────────────────────
+
+  listGuests(drawingId: string): DBGuest[] {
+    return this.db.prepare('SELECT * FROM guests WHERE drawing_id = ? ORDER BY created_at').all(drawingId) as DBGuest[];
+  }
+
+  getGuest(id: string): DBGuest | null {
+    return (this.db.prepare('SELECT * FROM guests WHERE id = ?').get(id) as DBGuest) ?? null;
+  }
+
+  createGuest(data: Partial<DBGuest>): DBGuest {
+    const id = data.id ?? randomUUID();
+    const created_at = new Date().toISOString();
+    this.db.prepare(
+      'INSERT INTO guests (id, drawing_id, name, email, category, seat_element_id, notes, created_at) VALUES (?, ?, ?, ?, ?, ?, ?, ?)'
+    ).run(id, data.drawing_id!, data.name!, data.email ?? null, data.category ?? 'standard', data.seat_element_id ?? null, data.notes ?? null, created_at);
+    return this.getGuest(id)!;
+  }
+
+  updateGuest(id: string, data: Partial<DBGuest>): DBGuest | null {
+    const existing = this.getGuest(id);
+    if (!existing) return null;
+    const merged = { ...existing, ...data, id: existing.id, drawing_id: existing.drawing_id, created_at: existing.created_at };
+    this.db.prepare(
+      'UPDATE guests SET name=?, email=?, category=?, seat_element_id=?, notes=? WHERE id=?'
+    ).run(merged.name, merged.email ?? null, merged.category, merged.seat_element_id ?? null, merged.notes ?? null, id);
+    return this.getGuest(id);
+  }
+
+  deleteGuest(id: string): boolean {
+    return this.db.prepare('DELETE FROM guests WHERE id = ?').run(id).changes > 0;
+  }
 }

backend/src/database/schema.sql

@@ -171,6 +171,7 @@ CREATE TABLE IF NOT EXISTS global_blocks (
   name TEXT NOT NULL,
   block_data TEXT NOT NULL DEFAULT '{}',
   svg_data TEXT,
+  is_favorite INTEGER NOT NULL DEFAULT 0,
   created_at TEXT NOT NULL DEFAULT (datetime('now')),
   updated_at TEXT NOT NULL DEFAULT (datetime('now')),
   FOREIGN KEY (folder_id) REFERENCES global_block_folders(id) ON DELETE SET NULL
@@ -178,3 +179,17 @@ CREATE TABLE IF NOT EXISTS global_blocks (
 
 CREATE INDEX IF NOT EXISTS idx_global_blocks_folder ON global_blocks(folder_id);
 CREATE INDEX IF NOT EXISTS idx_global_block_folders_parent ON global_block_folders(parent_id);
+
+-- ─── Guests (Task E6) ────────────────────────────────
+CREATE TABLE IF NOT EXISTS guests (
+  id TEXT PRIMARY KEY,
+  drawing_id TEXT NOT NULL,
+  name TEXT NOT NULL,
+  email TEXT,
+  category TEXT DEFAULT 'standard',
+  seat_element_id TEXT,
+  notes TEXT,
+  created_at TEXT NOT NULL DEFAULT (datetime('now')),
+  FOREIGN KEY (drawing_id) REFERENCES drawings(id) ON DELETE CASCADE
+);
+CREATE INDEX IF NOT EXISTS idx_guests_drawing ON guests(drawing_id);

backend/src/routes/globalBlocks.ts

@@ -3,9 +3,10 @@
  */
 import type { FastifyInstance } from 'fastify';
 import type { DatabaseInterface } from '../database/DatabaseInterface.js';
-import { requireAuth } from '../auth/authMiddleware.js';
+import { requireAuth, requireLibraryAdmin } from '../auth/authMiddleware.js';
 import type { AuthService } from '../auth/AuthService.js';
 import { validateName, validateIdParam } from '../utils/validation.js';
+import JSZip from 'jszip';
 
 export function registerGlobalBlockRoutes(fastify: FastifyInstance, db: DatabaseInterface, authService: AuthService) {
   // ─── Global Block Folders ──────────────────────────────
@@ -35,7 +36,7 @@ export function registerGlobalBlockRoutes(fastify: FastifyInstance, db: Database
 
   // Create a new folder
   fastify.post('/api/global-folders', async (request, reply) => {
-    if (!requireAuth(request, reply, authService)) return;
+    if (!requireLibraryAdmin(request, reply, authService)) return;
     const body = request.body as { name?: string; parent_id?: string | null };
     const nameErr = validateName(body.name, 'name');
     if (nameErr) return reply.code(400).send({ error: nameErr });
@@ -48,7 +49,7 @@ export function registerGlobalBlockRoutes(fastify: FastifyInstance, db: Database
 
   // Rename / move a folder
   fastify.patch('/api/global-folders/:id', async (request, reply) => {
-    if (!requireAuth(request, reply, authService)) return;
+    if (!requireLibraryAdmin(request, reply, authService)) return;
     const { id } = request.params as { id: string };
     const idErr = validateIdParam(id, 'id');
     if (idErr) return reply.code(400).send({ error: idErr });
@@ -70,7 +71,7 @@ export function registerGlobalBlockRoutes(fastify: FastifyInstance, db: Database
 
   // Delete a folder (cascades to children, blocks get folder_id = NULL)
   fastify.delete('/api/global-folders/:id', async (request, reply) => {
-    if (!requireAuth(request, reply, authService)) return;
+    if (!requireLibraryAdmin(request, reply, authService)) return;
     const { id } = request.params as { id: string };
     const idErr = validateIdParam(id, 'id');
     if (idErr) return reply.code(400).send({ error: idErr });
@@ -106,7 +107,7 @@ export function registerGlobalBlockRoutes(fastify: FastifyInstance, db: Database
 
   // Create a new global block
   fastify.post('/api/global-blocks', async (request, reply) => {
-    if (!requireAuth(request, reply, authService)) return;
+    if (!requireLibraryAdmin(request, reply, authService)) return;
     const body = request.body as { name?: string; folder_id?: string | null; block_data?: string; svg_data?: string };
     const nameErr = validateName(body.name, 'name');
     if (nameErr) return reply.code(400).send({ error: nameErr });
@@ -130,15 +131,18 @@ export function registerGlobalBlockRoutes(fastify: FastifyInstance, db: Database
 
   // Update a global block (rename, move, update data)
   fastify.patch('/api/global-blocks/:id', async (request, reply) => {
-    if (!requireAuth(request, reply, authService)) return;
+    if (!requireLibraryAdmin(request, reply, authService)) return;
     const { id } = request.params as { id: string };
     const idErr = validateIdParam(id, 'id');
     if (idErr) return reply.code(400).send({ error: idErr });
-    const body = request.body as { name?: string; folder_id?: string | null; block_data?: string; svg_data?: string };
+    const body = request.body as { name?: string; folder_id?: string | null; block_data?: string; svg_data?: string; is_favorite?: boolean };
     if (body.name !== undefined) {
       const nameErr = validateName(body.name, 'name');
       if (nameErr) return reply.code(400).send({ error: nameErr });
     }
+    if (body.is_favorite !== undefined && typeof body.is_favorite !== 'boolean') {
+      return reply.code(400).send({ error: 'is_favorite must be a boolean' });
+    }
     if (body.folder_id !== undefined && body.folder_id !== null) {
       const fidErr = validateIdParam(body.folder_id, 'folder_id');
       if (fidErr) return reply.code(400).send({ error: fidErr });
@@ -156,7 +160,7 @@ export function registerGlobalBlockRoutes(fastify: FastifyInstance, db: Database
 
   // Delete a global block
   fastify.delete('/api/global-blocks/:id', async (request, reply) => {
-    if (!requireAuth(request, reply, authService)) return;
+    if (!requireLibraryAdmin(request, reply, authService)) return;
     const { id } = request.params as { id: string };
     const idErr = validateIdParam(id, 'id');
     if (idErr) return reply.code(400).send({ error: idErr });
@@ -164,4 +168,194 @@ export function registerGlobalBlockRoutes(fastify: FastifyInstance, db: Database
     if (!ok) return reply.code(404).send({ error: 'Global block not found' });
     return reply.code(204).send();
   });
+
+  // ─── Task F1: Library-Paket Export/Import (.wcadlib) ──────
+
+  // Export: komplette Library als JSON-Paket (Ordner + Blöcke)
+  fastify.get('/api/global-blocks/export', async (request, reply) => {
+    if (!requireAuth(request, reply, authService)) return;
+    const folders = db.listGlobalFolders();
+    const blocks = db.listGlobalBlocks();
+    return {
+      format: 'wcadlib',
+      version: 1,
+      exported_at: new Date().toISOString(),
+      folders: folders.map((f) => ({ id: f.id, name: f.name, parent_id: f.parent_id })),
+      blocks: blocks.map((b) => ({
+        name: b.name,
+        folder_id: b.folder_id,
+        block_data: b.block_data,
+        svg_data: b.svg_data,
+      })),
+    };
+  });
+
+  // Import: .wcadlib-Paket einspielen (IDs neu, Ordner-Hierarchie über Mapping erhalten)
+  fastify.post('/api/global-blocks/import', async (request, reply) => {
+    if (!requireLibraryAdmin(request, reply, authService)) return;
+    const pkg = request.body as {
+      format?: string;
+      folders?: Array<{ id: string; name: string; parent_id: string | null }>;
+      blocks?: Array<{ name: string; folder_id: string | null; block_data: string; svg_data: string | null }>;
+    };
+    if (!pkg || pkg.format !== 'wcadlib' || !Array.isArray(pkg.blocks)) {
+      return reply.code(400).send({ error: 'Invalid wcadlib package (format != wcadlib or blocks missing)' });
+    }
+
+    // Ordner mit ID-Mapping importieren:
+    const folderIdMap = new Map<string, string>();
+    const sortedFolders = [...(pkg.folders ?? [])].sort((a, b) => {
+      if (a.parent_id === b.parent_id) return 0;
+      if (a.parent_id === null) return -1;
+      if (b.parent_id === null) return 1;
+      return 0;
+    });
+    for (const f of sortedFolders) {
+      const newParent = f.parent_id ? folderIdMap.get(f.parent_id) ?? null : null;
+      const created = db.createGlobalFolder({ name: f.name, parent_id: newParent });
+      folderIdMap.set(f.id, created.id);
+    }
+
+    // Blöcke importieren:
+    let imported = 0;
+    for (const b of pkg.blocks) {
+      const newFolderId = b.folder_id ? folderIdMap.get(b.folder_id) ?? null : null;
+      db.createGlobalBlock({
+        name: b.name,
+        folder_id: newFolderId,
+        block_data: b.block_data,
+        svg_data: b.svg_data,
+      });
+      imported++;
+    }
+    return reply.code(201).send({ imported_blocks: imported, imported_folders: folderIdMap.size });
+  });
+
+  // ─── Task F7: .wcadlib als echtes ZIP-Paket ──────────────
+
+  // ZIP-Export: manifest.json + blocks.json + thumbs/ (SVG je Block)
+  fastify.get('/api/global-blocks/export-zip', async (request, reply) => {
+    if (!requireAuth(request, reply, authService)) return;
+    const folders = db.listGlobalFolders();
+    const blocks = db.listGlobalBlocks();
+
+    const zip = new JSZip();
+    zip.file('manifest.json', JSON.stringify({
+      format: 'wcadlib-zip',
+      version: 1,
+      exported_at: new Date().toISOString(),
+      block_count: blocks.length,
+      folder_count: folders.length,
+    }));
+
+    const blockEntries = [] as Array<{
+      name: string;
+      folder_id: string | null;
+      block_data: string;
+      thumbnail: string | null;
+    }>;
+    for (const b of blocks) {
+      let thumbnail: string | null = null;
+      if (b.svg_data) {
+        thumbnail = `thumbs/${b.id}.svg`;
+        zip.file(thumbnail, b.svg_data);
+      }
+      blockEntries.push({
+        name: b.name,
+        folder_id: b.folder_id,
+        block_data: b.block_data,
+        thumbnail,
+      });
+    }
+    zip.file('blocks.json', JSON.stringify({
+      folders: folders.map((f) => ({ id: f.id, name: f.name, parent_id: f.parent_id })),
+      blocks: blockEntries,
+    }));
+
+    const buffer = await zip.generateAsync({ type: 'nodebuffer' });
+    reply.header('content-type', 'application/zip');
+    reply.header('content-disposition', 'attachment; filename="library.wcadlib.zip"');
+    return reply.send(buffer);
+  });
+
+  // ZIP-Import: .wcadlib-ZIP einspielen (Ordner-Mapping, Blöcke, Thumbnails)
+  fastify.post('/api/global-blocks/import-zip', async (request, reply) => {
+    if (!requireLibraryAdmin(request, reply, authService)) return;
+    const body = request.body;
+    if (!Buffer.isBuffer(body) || body.length === 0) {
+      return reply.code(400).send({ error: 'ZIP body fehlt oder leer' });
+    }
+
+    let zip: JSZip;
+    try {
+      zip = await JSZip.loadAsync(body);
+    } catch {
+      return reply.code(400).send({ error: 'Kein valides ZIP-Format' });
+    }
+
+    const blocksFile = zip.file('blocks.json');
+    if (!blocksFile) {
+      return reply.code(400).send({ error: 'blocks.json fehlt im ZIP' });
+    }
+
+    let pkg: { folders?: Array<{ id: string; name: string; parent_id: string | null }>; blocks?: Array<{ name: string; folder_id: string | null; block_data: string; thumbnail?: string | null }> };
+    try {
+      pkg = JSON.parse(await blocksFile.async('string'));
+    } catch {
+      return reply.code(400).send({ error: 'blocks.json ist kein valides JSON' });
+    }
+    if (!Array.isArray(pkg.blocks)) {
+      return reply.code(400).send({ error: 'blocks.json enthaelt kein blocks-Array' });
+    }
+
+    // Optional: manifest pruefen (falls vorhanden)
+    const manifestFile = zip.file('manifest.json');
+    if (manifestFile) {
+      try {
+        const manifest = JSON.parse(await manifestFile.async('string'));
+        if (manifest.format && manifest.format !== 'wcadlib-zip') {
+          return reply.code(400).send({ error: `Unbekanntes Paket-Format: ${manifest.format}` });
+        }
+      } catch {
+        return reply.code(400).send({ error: 'manifest.json ist kein valides JSON' });
+      }
+    }
+
+    // Ordner mit ID-Mapping importieren (Eltern zuerst):
+    const folderIdMap = new Map<string, string>();
+    const sortedFolders = [...(pkg.folders ?? [])].sort((a, b) => {
+      if (a.parent_id === null) return -1;
+      if (b.parent_id === null) return 1;
+      if (a.parent_id === b.parent_id) return 0;
+      const aRes = folderIdMap.has(a.parent_id!) ? -1 : 0;
+      return aRes;
+    });
+    for (const f of sortedFolders) {
+      const newParent = f.parent_id ? folderIdMap.get(f.parent_id) ?? null : null;
+      const created = db.createGlobalFolder({ name: f.name, parent_id: newParent });
+      folderIdMap.set(f.id, created.id);
+    }
+
+    // Blöcke importieren; Thumbnail aus thumbs/ lesen wenn referenziert:
+    let imported = 0;
+    for (const b of pkg.blocks) {
+      let svgData: string | null = null;
+      if (b.thumbnail) {
+        const thumbFile = zip.file(b.thumbnail);
+        if (thumbFile) {
+          try { svgData = await thumbFile.async('string'); } catch { svgData = null; }
+        }
+      }
+      const newFolderId = b.folder_id ? folderIdMap.get(b.folder_id) ?? null : null;
+      db.createGlobalBlock({
+        name: b.name,
+        folder_id: newFolderId,
+        block_data: b.block_data,
+        svg_data: svgData,
+      });
+      imported++;
+    }
+
+    return reply.code(201).send({ imported_blocks: imported, imported_folders: folderIdMap.size });
+  });
 }

backend/src/routes/guests.ts

@@ -0,0 +1,63 @@
+/**
+ * Guests Routes – CRUD for event guests (Task E6)
+ */
+import type { FastifyInstance } from 'fastify';
+import type { DatabaseInterface } from '../database/DatabaseInterface.js';
+import { requireAuth } from '../auth/authMiddleware.js';
+import type { AuthService } from '../auth/AuthService.js';
+import { validateIdParam } from '../utils/validation.js';
+
+export function registerGuestRoutes(fastify: FastifyInstance, db: DatabaseInterface, authService: AuthService) {
+  // List guests for a drawing
+  fastify.get('/api/drawings/:drawingId/guests', async (request, reply) => {
+    if (!requireAuth(request, reply, authService)) return;
+    const { drawingId } = request.params as { drawingId: string };
+    const idErr = validateIdParam(drawingId, 'drawingId');
+    if (idErr) return reply.code(400).send({ error: idErr });
+    return db.listGuests(drawingId);
+  });
+
+  // Create guest
+  fastify.post('/api/drawings/:drawingId/guests', async (request, reply) => {
+    if (!requireAuth(request, reply, authService)) return;
+    const { drawingId } = request.params as { drawingId: string };
+    const idErr = validateIdParam(drawingId, 'drawingId');
+    if (idErr) return reply.code(400).send({ error: idErr });
+    const body = request.body as { name?: string; email?: string; category?: string; seat_element_id?: string; notes?: string };
+    if (!body.name || typeof body.name !== 'string' || body.name.trim() === '') {
+      return reply.code(400).send({ error: 'name is required' });
+    }
+    const guest = db.createGuest({
+      drawing_id: drawingId,
+      name: body.name.trim(),
+      email: body.email,
+      category: body.category ?? 'standard',
+      seat_element_id: body.seat_element_id,
+      notes: body.notes,
+    });
+    return reply.code(201).send(guest);
+  });
+
+  // Update guest
+  fastify.patch('/api/guests/:id', async (request, reply) => {
+    if (!requireAuth(request, reply, authService)) return;
+    const { id } = request.params as { id: string };
+    const idErr = validateIdParam(id, 'id');
+    if (idErr) return reply.code(400).send({ error: idErr });
+    const body = request.body as Partial<{ name: string; email: string; category: string; seat_element_id: string; notes: string }>;
+    const updated = db.updateGuest(id, body);
+    if (!updated) return reply.code(404).send({ error: 'Guest not found' });
+    return updated;
+  });
+
+  // Delete guest
+  fastify.delete('/api/guests/:id', async (request, reply) => {
+    if (!requireAuth(request, reply, authService)) return;
+    const { id } = request.params as { id: string };
+    const idErr = validateIdParam(id, 'id');
+    if (idErr) return reply.code(400).send({ error: idErr });
+    const ok = db.deleteGuest(id);
+    if (!ok) return reply.code(404).send({ error: 'Guest not found' });
+    return reply.code(204).send();
+  });
+}

backend/src/server.ts

@@ -22,6 +22,11 @@ export interface ServerOptions {
 export async function createServer(opts: ServerOptions) {
   const fastify = Fastify({ logger: true });
 
+  // ─── Task F7: binäre Body für .wcadlib ZIP-Import ───
+  fastify.addContentTypeParser('application/zip', { parseAs: 'buffer' }, (_req, body, done) => done(null, body));
+  fastify.addContentTypeParser('application/octet-stream', { parseAs: 'buffer' }, (_req, body, done) => done(null, body));
+  fastify.addContentTypeParser('application/x-zip-compressed', { parseAs: 'buffer' }, (_req, body, done) => done(null, body));
+
   // CORS — restrictive origin list
   await fastify.register(cors, {
     origin: (origin: string | undefined, cb: (err: Error | null, allow: boolean) => void) => {
@@ -66,6 +71,7 @@ export async function createServer(opts: ServerOptions) {
   const { registerAIRoutes } = await import('./routes/ai.js');
   const { registerNotificationRoutes } = await import('./routes/notifications.js');
   const { registerShareRoutes } = await import('./routes/shares.js');
+  const { registerGuestRoutes } = await import('./routes/guests.js');
   const { registerGlobalBlockRoutes } = await import('./routes/globalBlocks.js');
   const { registerProjectFolderRoutes } = await import('./routes/projectFolders.js');
 
@@ -103,6 +109,7 @@ export async function createServer(opts: ServerOptions) {
   registerNotificationRoutes(fastify, opts.db, authService);
   registerShareRoutes(fastify, opts.db, authService);
   registerGlobalBlockRoutes(fastify, opts.db, authService);
+  registerGuestRoutes(fastify, opts.db, authService);
   registerProjectFolderRoutes(fastify, opts.db, authService);
 
   // Yjs collaboration WebSocket

backend/tests/SqliteAdapter.test.ts

@@ -381,3 +381,72 @@ describe('SqliteAdapter', () => {
     });
   });
 });
+
+// ─── ID-Kollisionsklasse: Date.now() → randomUUID (BUG-1-Familie) ──
+// Deterministischer Beweis: Date.now() wird via Fake-Timers EINGEFROREN,
+// damit zwei Creates garantiert im selben Tick landen. Mit Date.now()-IDs
+// kollidiert der zweite INSERT am PRIMARY KEY (UNIQUE-Exception); mit
+// randomUUID sind die IDs stets eindeutig.
+import { vi } from 'vitest';
+const FROZEN_NOW = 1756000000000;
+
+describe('SqliteAdapter – auto-ID uniqueness within same tick', () => {
+  let db: SqliteAdapter;
+
+  beforeAll(async () => {
+    vi.useFakeTimers();
+    vi.setSystemTime(FROZEN_NOW);
+    db = new SqliteAdapter(':memory:');
+    await db.init();
+  });
+
+  afterAll(() => {
+    db.close();
+    vi.useRealTimers();
+  });
+
+  it('createUser liefert unterschiedliche IDs bei zwei Creates im selben Tick', () => {
+    const a = db.createUser({ email: `tick-a-${Date.now()}@x.de`, password_hash: 'h', name: 'A' });
+    const b = db.createUser({ email: `tick-b-${Date.now()}@x.de`, password_hash: 'h', name: 'B' });
+    expect(b.id).not.toBe(a.id);
+  });
+
+  it('createProject/createProjectFolder liefern unterschiedliche IDs im selben Tick', () => {
+    const p1 = db.createProject({ name: 'P1' });
+    const p2 = db.createProject({ name: 'P2' });
+    expect(p2.id).not.toBe(p1.id);
+    const f1 = db.createProjectFolder({ name: 'F1' });
+    const f2 = db.createProjectFolder({ name: 'F2' });
+    expect(f2.id).not.toBe(f1.id);
+  });
+
+  it('createDrawing/createLayer/createElement/createBlock liefern unterschiedliche IDs im selben Tick', () => {
+    const proj = db.createProject({ name: 'DrawHost' });
+    const d1 = db.createDrawing({ project_id: proj.id, name: 'D1' });
+    const d2 = db.createDrawing({ project_id: proj.id, name: 'D2' });
+    expect(d2.id).not.toBe(d1.id);
+
+    const l1 = db.createLayer({ drawing_id: d1.id, name: 'L1' });
+    const l2 = db.createLayer({ drawing_id: d1.id, name: 'L2' });
+    expect(l2.id).not.toBe(l1.id);
+
+    const e1 = db.createElement({ drawing_id: d1.id, layer_id: l1.id, type: 'line' });
+    const e2 = db.createElement({ drawing_id: d1.id, layer_id: l1.id, type: 'line' });
+    expect(e2.id).not.toBe(e1.id);
+
+    const b1 = db.createBlock({ drawing_id: d1.id, name: 'B1' });
+    const b2 = db.createBlock({ drawing_id: d1.id, name: 'B2' });
+    expect(b2.id).not.toBe(b1.id);
+  });
+
+  it('createNotification/createProjectShare liefern unterschiedliche IDs im selben Tick', () => {
+    const proj = db.createProject({ name: 'ShareHost' });
+    const n1 = db.createNotification({ user_id: 'user-default', title: 'T1', message: 'M1' });
+    const n2 = db.createNotification({ user_id: 'user-default', title: 'T2', message: 'M2' });
+    expect(n2.id).not.toBe(n1.id);
+
+    const s1 = db.createProjectShare({ project_id: proj.id, shared_with_email: 'a@x.de', shared_by: 'user-default' });
+    const s2 = db.createProjectShare({ project_id: proj.id, shared_with_email: 'b@x.de', shared_by: 'user-default' });
+    expect(s2.id).not.toBe(s1.id);
+  });
+});

backend/tests/globalBlocks.test.ts

@@ -424,3 +424,191 @@ describe('Global Blocks API', () => {
     });
   });
 });
+
+// ─── Task F1: Library-Paket Export/Import (.wcadlib) ──────
+
+describe('Global Blocks API – F1 export/import', () => {
+  let app: FastifyInstance;
+  let db: SqliteAdapter;
+  let authToken: string;
+
+  beforeAll(async () => {
+    db = new SqliteAdapter(':memory:');
+    await db.init();
+    app = await createServer({ db, port: 0 });
+    await app.ready();
+    const regRes = await app.inject({
+      method: 'POST',
+      url: '/api/auth/register',
+      payload: { email: 'f1-export@example.com', password: 'Password123!', name: 'F1 Test', role: 'admin' },
+    });
+    authToken = JSON.parse(regRes.body).session.token;
+  });
+
+  afterAll(async () => {
+    await app.close();
+    db.close();
+  });
+
+  it('GET /api/global-blocks/export liefert wcadlib-Paket mit folders+blocks', async () => {
+    // Setup: 1 Ordner + 1 Block
+    const folder = await app.inject({
+      method: 'POST',
+      url: '/api/global-folders',
+      headers: { authorization: `Bearer ${authToken}` },
+      payload: { name: 'F1-Ordner' },
+    });
+    const folderId = JSON.parse(folder.body).id;
+    await app.inject({
+      method: 'POST',
+      url: '/api/global-blocks',
+      headers: { authorization: `Bearer ${authToken}` },
+      payload: { name: 'F1-Block', folder_id: folderId, block_data: '{"type":"rect"}' },
+    });
+
+    const res = await app.inject({
+      method: 'GET',
+      url: '/api/global-blocks/export',
+      headers: { authorization: `Bearer ${authToken}` },
+    });
+    expect(res.statusCode).toBe(200);
+    const pkg = JSON.parse(res.body);
+    expect(pkg.format).toBe('wcadlib');
+    expect(Array.isArray(pkg.folders)).toBe(true);
+    expect(Array.isArray(pkg.blocks)).toBe(true);
+    expect(pkg.folders.length).toBeGreaterThanOrEqual(1);
+    expect(pkg.blocks.length).toBeGreaterThanOrEqual(1);
+  });
+
+  it('POST /api/global-blocks/import spielt Paket mit Ordner-Mapping ein', async () => {
+    const pkg = {
+      format: 'wcadlib',
+      version: 1,
+      folders: [
+        { id: 'src-folder-1', name: 'Import-Ordner', parent_id: null },
+      ],
+      blocks: [
+        { name: 'Import-Block', folder_id: 'src-folder-1', block_data: '{"type":"circle"}', svg_data: null },
+        { name: 'Import-Block-Root', folder_id: null, block_data: '{}', svg_data: null },
+      ],
+    };
+    const res = await app.inject({
+      method: 'POST',
+      url: '/api/global-blocks/import',
+      headers: { authorization: `Bearer ${authToken}` },
+      payload: pkg,
+    });
+    expect(res.statusCode, res.body).toBe(201);
+    const body = JSON.parse(res.body);
+    expect(body.imported_blocks).toBe(2);
+    expect(body.imported_folders).toBe(1);
+
+    // Block im importierten Ordner auffindbar:
+    const blocks = await app.inject({
+      method: 'GET',
+      url: '/api/global-blocks',
+      headers: { authorization: `Bearer ${authToken}` },
+    });
+    const list = JSON.parse(blocks.body) as Array<{ name: string; folder_id: string | null }>;
+    const importedBlock = list.find((b) => b.name === 'Import-Block');
+    expect(importedBlock).toBeDefined();
+    expect(importedBlock!.folder_id).not.toBeNull(); // Mapping erhalten
+  });
+
+  it('Import mit falschem format liefert 400', async () => {
+    const res = await app.inject({
+      method: 'POST',
+      url: '/api/global-blocks/import',
+      headers: { authorization: `Bearer ${authToken}` },
+      payload: { format: 'wrong', blocks: [] },
+    });
+    expect(res.statusCode).toBe(400);
+  });
+});
+
+// ─── Task F2: Block-Favoriten ─────────────────────────────
+describe('Global Blocks API – F2 favorite', () => {
+  let app: FastifyInstance;
+  let db: SqliteAdapter;
+  let authToken: string;
+  let blockId: string;
+
+  beforeAll(async () => {
+    db = new SqliteAdapter(':memory:');
+    await db.init();
+    app = await createServer({ db, port: 0 });
+    await app.ready();
+
+    const regRes = await app.inject({
+      method: 'POST',
+      url: '/api/auth/register',
+      payload: { email: 'fav-test@example.com', password: 'Password123!', name: 'Fav Test', role: 'admin' },
+    });
+    authToken = JSON.parse(regRes.body).session.token;
+
+    const blockRes = await app.inject({
+      method: 'POST',
+      url: '/api/global-blocks',
+      headers: { authorization: `Bearer ${authToken}` },
+      payload: { name: 'Fav-Block', block_data: '{"type":"block"}' },
+    });
+    blockId = JSON.parse(blockRes.body).id;
+  });
+
+  afterAll(async () => {
+    await app.close();
+    db.close();
+  });
+
+  it('neuer Block startet mit is_favorite=false', async () => {
+    const res = await app.inject({
+      method: 'GET',
+      url: `/api/global-blocks/${blockId}`,
+      headers: { authorization: `Bearer ${authToken}` },
+    });
+    expect(res.statusCode).toBe(200);
+    expect(JSON.parse(res.body).is_favorite).toBe(false);
+  });
+
+  it('PATCH is_favorite:true setzt Favorit', async () => {
+    const res = await app.inject({
+      method: 'PATCH',
+      url: `/api/global-blocks/${blockId}`,
+      headers: { authorization: `Bearer ${authToken}` },
+      payload: { is_favorite: true },
+    });
+    expect(res.statusCode).toBe(200);
+    expect(JSON.parse(res.body).is_favorite).toBe(true);
+  });
+
+  it('is_favorite ist persistent nach GET', async () => {
+    const res = await app.inject({
+      method: 'GET',
+      url: `/api/global-blocks/${blockId}`,
+      headers: { authorization: `Bearer ${authToken}` },
+    });
+    expect(res.statusCode).toBe(200);
+    expect(JSON.parse(res.body).is_favorite).toBe(true);
+  });
+
+  it('PATCH is_favorite:false hebt Favorit auf', async () => {
+    const res = await app.inject({
+      method: 'PATCH',
+      url: `/api/global-blocks/${blockId}`,
+      headers: { authorization: `Bearer ${authToken}` },
+      payload: { is_favorite: false },
+    });
+    expect(res.statusCode).toBe(200);
+    expect(JSON.parse(res.body).is_favorite).toBe(false);
+  });
+
+  it('PATCH mit nicht-boolean is_favorite liefert 400', async () => {
+    const res = await app.inject({
+      method: 'PATCH',
+      url: `/api/global-blocks/${blockId}`,
+      headers: { authorization: `Bearer ${authToken}` },
+      payload: { is_favorite: 'yes' },
+    });
+    expect(res.statusCode).toBe(400);
+  });
+});

backend/tests/globalBlocksZip.test.ts

@@ -0,0 +1,164 @@
+/**
+ * Task F7 – .wcadlib ZIP-Paket Export/Import (Backend).
+ *
+ * ZIP-Struktur: manifest.json (format/version/exported_at), blocks.json
+ * (Ordner + Blöcke), thumbs/ (SVG-Thumbnails je Block-ID). Export liefert
+ * application/zip; Import parst das ZIP und spielt Ordner-Hierarchie +
+ * Blöcke mit ID-Mapping ein. Invalides ZIP → 400.
+ */
+import { describe, it, expect, beforeAll, afterAll } from 'vitest';
+import type { FastifyInstance } from 'fastify';
+import JSZip from 'jszip';
+import { SqliteAdapter } from '../src/database/SqliteAdapter.js';
+import { createServer } from '../src/server.js';
+
+describe('Task F7: .wcadlib ZIP Export/Import', () => {
+  let app: FastifyInstance;
+  let db: SqliteAdapter;
+  let token: string;
+
+  beforeAll(async () => {
+    db = new SqliteAdapter(':memory:');
+    await db.init();
+    app = await createServer({ db, port: 0 });
+    await app.ready();
+
+    const regRes = await app.inject({
+      method: 'POST',
+      url: '/api/auth/register',
+      payload: { email: 'f7-zip@example.com', password: 'Password123!', name: 'F7 Zip', role: 'admin' },
+    });
+    token = JSON.parse(regRes.body).session.token;
+  });
+
+  afterAll(async () => {
+    await app.close();
+    db.close();
+  });
+
+  async function createFixture(): Promise<{ folderId: string; blockId: string }> {
+    const folderRes = await app.inject({
+      method: 'POST',
+      url: '/api/global-folders',
+      headers: { authorization: `Bearer ${token}` },
+      payload: { name: 'Event Set', parent_id: null },
+    });
+    const folderId = JSON.parse(folderRes.body).id;
+    const blockRes = await app.inject({
+      method: 'POST',
+      url: '/api/global-blocks',
+      headers: { authorization: `Bearer ${token}` },
+      payload: {
+        name: 'Stuhl-Reihe',
+        folder_id: folderId,
+        block_data: JSON.stringify([{ id: 'e1', type: 'chair', x: 0, y: 0, width: 45, height: 45, properties: {} }]),
+        svg_data: '<svg xmlns="http://www.w3.org/2000/svg"><rect/></svg>',
+      },
+    });
+    const blockId = JSON.parse(blockRes.body).id;
+    return { folderId, blockId };
+  }
+
+  it('GET /api/global-blocks/export-zip liefert ZIP mit manifest.json, blocks.json und thumbs/', async () => {
+    const { blockId } = await createFixture();
+    const res = await app.inject({
+      method: 'GET',
+      url: '/api/global-blocks/export-zip',
+      headers: { authorization: `Bearer ${token}` },
+    });
+    expect(res.statusCode).toBe(200);
+    expect(res.headers['content-type']).toContain('application/zip');
+
+    const zip = await JSZip.loadAsync(res.rawPayload ?? res.body);
+    expect(zip.file('manifest.json')).toBeDefined();
+    expect(zip.file('blocks.json')).toBeDefined();
+
+    const manifest = JSON.parse(await zip.file('manifest.json')!.async('string'));
+    expect(manifest.format).toBe('wcadlib-zip');
+    expect(manifest.version).toBe(1);
+    expect(typeof manifest.exported_at).toBe('string');
+
+    const blocks = JSON.parse(await zip.file('blocks.json')!.async('string'));
+    expect(blocks.folders.length).toBe(1);
+    expect(blocks.folders[0].name).toBe('Event Set');
+    expect(blocks.blocks.length).toBeGreaterThanOrEqual(1);
+    const chairBlock = blocks.blocks.find((b: { name: string }) => b.name === 'Stuhl-Reihe');
+    expect(chairBlock).toBeDefined();
+    expect(chairBlock.thumbnail).toBe(`thumbs/${blockId}.svg`);
+
+    const thumb = zip.file(`thumbs/${blockId}.svg`);
+    expect(thumb).toBeDefined();
+    expect(await thumb!.async('string')).toContain('<svg');
+  });
+
+  it('Export ohne Auth → 401', async () => {
+    const res = await app.inject({ method: 'GET', url: '/api/global-blocks/export-zip' });
+    expect(res.statusCode).toBe(401);
+  });
+
+  it('POST /api/global-blocks/import-zip spielt ZIP ein (Ordner-Mapping + Blöcke + Thumb-Referenz erhalten)', async () => {
+    const { blockId } = await createFixture();
+    const exportRes = await app.inject({
+      method: 'GET',
+      url: '/api/global-blocks/export-zip',
+      headers: { authorization: `Bearer ${token}` },
+    });
+    expect(exportRes.statusCode).toBe(200);
+    const zipBuffer = exportRes.rawPayload ?? exportRes.body;
+
+    const importRes = await app.inject({
+      method: 'POST',
+      url: '/api/global-blocks/import-zip',
+      headers: {
+        authorization: `Bearer ${token}`,
+        'content-type': 'application/zip',
+      },
+      payload: zipBuffer,
+    });
+    expect(importRes.statusCode).toBe(201);
+    const body = JSON.parse(importRes.body);
+    expect(body.imported_blocks).toBeGreaterThanOrEqual(1);
+    expect(body.imported_folders).toBeGreaterThanOrEqual(1);
+
+    // Verifizieren: importierter Block existiert mit Thumb-Daten
+    const blocksRes = await app.inject({
+      method: 'GET',
+      url: '/api/global-blocks',
+      headers: { authorization: `Bearer ${token}` },
+    });
+    const allBlocks = JSON.parse(blocksRes.body);
+    const imported = allBlocks.filter((b: { name: string }) => b.name === 'Stuhl-Reihe');
+    expect(imported.length).toBeGreaterThanOrEqual(2); // Original + Import
+    expect(imported.every((b: { svg_data: string | null }) => b.svg_data !== null)).toBe(true);
+  });
+
+  it('Import mit Müll-Payload → 400 (kein valides ZIP)', async () => {
+    const res = await app.inject({
+      method: 'POST',
+      url: '/api/global-blocks/import-zip',
+      headers: {
+        authorization: `Bearer ${token}`,
+        'content-type': 'application/zip',
+      },
+      payload: Buffer.from('dies ist kein zip'),
+    });
+    expect(res.statusCode).toBe(400);
+    expect(JSON.parse(res.body).error).toContain('ZIP');
+  });
+
+  it('Import-ZIP ohne blocks.json → 400', async () => {
+    const zip = new JSZip();
+    zip.file('manifest.json', JSON.stringify({ format: 'wcadlib-zip', version: 1 }));
+    const buf = await zip.generateAsync({ type: 'nodebuffer' });
+    const res = await app.inject({
+      method: 'POST',
+      url: '/api/global-blocks/import-zip',
+      headers: {
+        authorization: `Bearer ${token}`,
+        'content-type': 'application/zip',
+      },
+      payload: buf,
+    });
+    expect(res.statusCode).toBe(400);
+  });
+});

backend/tests/libraryAdminGuard.test.ts

@@ -0,0 +1,160 @@
+/**
+ * Task H3 – Rollen: library-admin (global write) vs. user (read-only).
+ *
+ * requireLibraryAdmin schützt alle schreibenden Global-Library-Routen:
+ * POST/PATCH/DELETE auf folders+blocks, import, import-zip. Lesen
+ * (GET, export) bleibt für alle authentifizierten Nutzer offen.
+ * library-admin ist an die bestehende admin-Rolle angebunden.
+ */
+import { describe, it, expect, beforeAll, afterAll } from 'vitest';
+import type { FastifyInstance } from 'fastify';
+import { SqliteAdapter } from '../src/database/SqliteAdapter.js';
+import { createServer } from '../src/server.js';
+
+describe('Task H3: library-admin Guard', () => {
+  let app: FastifyInstance;
+  let db: SqliteAdapter;
+  let adminToken: string;
+  let planerToken: string;
+
+  beforeAll(async () => {
+    db = new SqliteAdapter(':memory:');
+    await db.init();
+    app = await createServer({ db, port: 0 });
+    await app.ready();
+
+    const adminReg = await app.inject({
+      method: 'POST',
+      url: '/api/auth/register',
+      payload: { email: 'h3-admin@example.com', password: 'Password123!', name: 'H3 Admin', role: 'admin' },
+    });
+    if (adminReg.statusCode !== 201) console.error('ADMIN REG FAILED:', adminReg.statusCode, adminReg.body.slice(0, 200));
+    adminToken = JSON.parse(adminReg.body).session?.token ?? '';
+
+    const planerReg = await app.inject({
+      method: 'POST',
+      url: '/api/auth/register',
+      payload: { email: 'h3-planer@example.com', password: 'Password123!', name: 'H3 Planer', role: 'planer' },
+    });
+    if (planerReg.statusCode !== 201) console.error('PLANER REG FAILED:', planerReg.statusCode, planerReg.body.slice(0, 200));
+    planerToken = JSON.parse(planerReg.body).session?.token ?? '';
+    admin = { authorization: `Bearer ${adminToken}` };
+    planer = { authorization: `Bearer ${planerToken}` };
+  });
+
+  afterAll(async () => {
+    await app.close();
+    db.close();
+  });
+
+  // WICHTIG: Header-Objekte werden in beforeAll gebaut — der describe-Body
+  // läuft VOR den Hooks, Template-Literale würden undefined capturen.
+  let planer: Record<string, string>;
+  let admin: Record<string, string>;
+
+  // ── Lesen bleibt offen (beide Rollen) ──
+
+  it('planer kann globale Ordner LESEN (200)', async () => {
+    const res = await app.inject({ method: 'GET', url: '/api/global-folders', headers: planer });
+    expect(res.statusCode).toBe(200);
+  });
+
+  it('planer kann globale Blöcke LESEN (200)', async () => {
+    const res = await app.inject({ method: 'GET', url: '/api/global-blocks', headers: planer });
+    expect(res.statusCode).toBe(200);
+  });
+
+  it('planer kann Library EXPORTIEREN (GET export, 200)', async () => {
+    const res = await app.inject({ method: 'GET', url: '/api/global-blocks/export', headers: planer });
+    expect(res.statusCode).toBe(200);
+  });
+
+  // ── Schreiben nur für library-admin (admin-Rolle) ──
+
+  it('planer POST /api/global-folders → 403', async () => {
+    const res = await app.inject({
+      method: 'POST', url: '/api/global-folders', headers: planer,
+      payload: { name: 'Verboten', parent_id: null },
+    });
+    expect(res.statusCode).toBe(403);
+    expect(JSON.parse(res.body).error).toContain('Library');
+  });
+
+  it('planer POST /api/global-blocks → 403', async () => {
+    const res = await app.inject({
+      method: 'POST', url: '/api/global-blocks', headers: planer,
+      payload: { name: 'Verboten', block_data: '[]' },
+    });
+    expect(res.statusCode).toBe(403);
+  });
+
+  it('planer PATCH /api/global-folders/:id → 403', async () => {
+    const res = await app.inject({
+      method: 'PATCH', url: '/api/global-folders/irgendeine-id', headers: planer,
+      payload: { name: 'Hack' },
+    });
+    expect(res.statusCode).toBe(403);
+  });
+
+  it('planer PATCH /api/global-blocks/:id → 403', async () => {
+    const res = await app.inject({
+      method: 'PATCH', url: '/api/global-blocks/irgendeine-id', headers: planer,
+      payload: { name: 'Hack' },
+    });
+    expect(res.statusCode).toBe(403);
+  });
+
+  it('planer DELETE /api/global-folders/:id → 403', async () => {
+    const res = await app.inject({ method: 'DELETE', url: '/api/global-folders/irgendeine-id', headers: planer });
+    expect(res.statusCode).toBe(403);
+  });
+
+  it('planer DELETE /api/global-blocks/:id → 403', async () => {
+    const res = await app.inject({ method: 'DELETE', url: '/api/global-blocks/irgendeine-id', headers: planer });
+    expect(res.statusCode).toBe(403);
+  });
+
+  it('planer POST /api/global-blocks/import → 403', async () => {
+    const res = await app.inject({
+      method: 'POST', url: '/api/global-blocks/import', headers: planer,
+      payload: { format: 'wcadlib', blocks: [] },
+    });
+    expect(res.statusCode).toBe(403);
+  });
+
+  it('planer POST /api/global-blocks/import-zip → 403', async () => {
+    const res = await app.inject({
+      method: 'POST', url: '/api/global-blocks/import-zip', headers: { ...planer, 'content-type': 'application/zip' },
+      payload: Buffer.from('PK'),
+    });
+    expect(res.statusCode).toBe(403);
+  });
+
+  // ── Admin (library-admin) darf schreiben ──
+
+  it('admin POST /api/global-folders → 201 (write erlaubt)', async () => {
+    const res = await app.inject({
+      method: 'POST', url: '/api/global-folders', headers: admin,
+      payload: { name: 'Admin Set', parent_id: null },
+    });
+    expect(res.statusCode).toBe(201);
+  });
+
+  it('admin POST /api/global-blocks → 201 (write erlaubt)', async () => {
+    const res = await app.inject({
+      method: 'POST', url: '/api/global-blocks', headers: admin,
+      payload: { name: 'Admin Block', block_data: '[]', folder_id: null },
+    });
+    expect(res.statusCode).toBe(201);
+  });
+
+  // ── Unauthentifiziert bleibt 401 ──
+
+  it('ohne Token POST /api/global-folders → 401 (nicht 403)', async () => {
+    const res = await app.inject({
+      method: 'POST', url: '/api/global-folders',
+      payload: { name: 'Anon', parent_id: null },
+    });
+    expect(res.statusCode).toBe(401);
+  });
+});

docs/LIBRARY_SPEC.md

@@ -0,0 +1,80 @@
+# .wcadlib – Block-Bibliotheks-Paket-Spezifikation
+
+WebCAD-Block-Bibliotheken können als `.wcadlib`-Paket geteilt werden.
+Es gibt zwei Formate:
+
+## Format 1: JSON-Paket (F1)
+
+Ein einzelnes JSON-File mit folgender Struktur:
+
+```json
+{
+  "format": "wcadlib",
+  "version": 1,
+  "exported_at": "2026-08-29T00:00:00.000Z",
+  "folders": [
+    { "id": "f1", "name": "Veranstaltungstechnik", "parent_id": null }
+  ],
+  "blocks": [
+    {
+      "name": "Stuhl-Reihe",
+      "folder_id": "f1",
+      "block_data": "[{...CADElement-Array als JSON-String...]}",
+      "svg_data": "<svg ...>"
+    }
+  ]
+}
+```
+
+- `block_data` = JSON-String eines **CADElement-Arrays**
+- `svg_data` = eigenständiges SVG (Thumbnail), optional
+- Ordner-Hierarchie via `parent_id` (Import ordnet IDs neu zu)
+
+**Endpoints:** `GET /api/global-blocks/export`, `POST /api/global-blocks/import`
+(schreibend: nur library-admin/Rolle admin, siehe H3)
+
+## Format 2: ZIP-Paket (F7)
+
+Ein echtes ZIP-Archiv mit fester Struktur:
+
+```
+library.wcadlib.zip
+├── manifest.json      { "format": "wcadlib-zip", "version": 1,
+│                       "exported_at": "...", "block_count": N, "folder_count": M }
+├── blocks.json        { "folders": [...], "blocks": [
+│                        { "name", "folder_id", "block_data",
+│                          "thumbnail": "thumbs/<id>.svg" } ] }
+└── thumbs/
+    └── <blockId>.svg   Thumbnails, Referenz aus blocks.json
+```
+
+- `manifest.format` MUSS `wcadlib-zip` sein (sonst 400)
+- `blocks.json` MUSS vorhanden sein (sonst 400); `blocks`-Array Pflicht
+- `thumbnail` verweist relativ auf `thumbs/<id>.svg`
+
+**Endpoints:**
+- `GET /api/global-blocks/export-zip` → `application/zip`
+- `POST /api/global-blocks/import-zip` (Body = ZIP als application/zip;
+  schreibend: nur library-admin)
+
+## Validierungsregeln (Import)
+
+| Fehler | HTTP |
+|---|---|
+| Kein valides ZIP (Format 2) | 400 |
+| blocks.json fehlt / invalides JSON | 400 |
+| manifest.format unbekannt | 400 |
+| Kein JSON/blocks-Array (Format 1) | 400 |
+| Nicht authentifiziert | 401 |
+| Rolle != admin (schreibend) | 403 |
+
+## CAD-Element-Konventionen (block_data)
+
+- `rect`: `x/y` = **Zentrum** der BBox
+- `circle`/`arc`: `el.x/el.y` = **Zentrum**, Winkel in Grad (0° = 3 Uhr, CCW)
+- `line`: `properties.x1/y1/x2/y2`
+- `polyline`/`polygon`: `properties.points`
+- `block_instance`: `properties.blockId` + optional `attrValues` (D12)
+
+Beim Drop auf die Zeichenfläche werden Element-IDs neu generiert und
+die Position per Drop-Punkt übersetzt – der Bestand bleibt unverändert.

docs/PLUGIN_GUIDE.md

@@ -0,0 +1,139 @@
+# Plugin Guide – WebCAD Plugin API v2
+
+WebCAD Plugin API v2 erlaubt die Erweiterung des CAD um Werkzeuge,
+Panels und Block-Bibliotheken – ohne Kerncode anzufassen.
+
+## Plugin-Typ (PluginV2)
+
+```ts
+import type { PluginV2, ToolExtensionV2 } from './plugins';
+
+export const myPlugin: PluginV2 = {
+  manifest: {
+    id: 'my-tools',
+    name: 'Meine Werkzeuge',
+    version: '1.0.0',
+    author: 'Du',
+    description: 'Beschreibung',
+    category: 'tools',        // tools|elements|library|import-export|theme|other
+    enabledByDefault: true,
+  },
+  tools: [/* ToolExtensionV2[] */],
+  panels: [/* PanelExtension[] (optional) */],
+  libraryProviders: [/* LibraryProviderExtension[] (optional) */],
+  onInit?() {}, onActivate?() {}, onDeactivate?() {}, onDestroy?() {},
+};
+```
+
+## Werkzeug (ToolExtensionV2)
+
+Ein Werkzeug besteht aus Manifest, Options-Schema und Handlern:
+
+```ts
+export const myTool: ToolExtensionV2 = {
+  manifest: {
+    id: 'my-tool',
+    label: 'Mein Werkzeug',
+    icon: 'M',
+    ribbonTab: 'canvas',   // canvas|insert|format
+    tags: ['basic'],        // basic = sichtbar im simple-Mode, ['pro'] nur pro-Mode
+    description: 'Was es tut',
+  },
+  optionsSchema: [
+    { key: 'width', label: 'Breite', type: 'number', min: 1, max: 500 },
+    { key: 'color', label: 'Farbe', type: 'color' },
+    { key: 'style', label: 'Stil', type: 'select',
+      options: [{ value: 'a', label: 'A' }, { value: 'b', label: 'B' }] },
+    { key: 'frame', label: 'Rahmen', type: 'checkbox' },
+  ],
+  handlers: {
+    down(e, ctx) {
+      // e.world = Weltkoordinaten, e.shift, e.ctrl
+      // ctx.doc = CADDocument (CRUD + transact + undo)
+      // ctx.setStatus('...'), ctx.setPreview?.(element)
+      const c = ctx as FullToolContext;
+      if (!c.doc) return;
+      c.doc.transact(() => c.doc!.addElement({ /* CADElement */ }));
+    },
+    move(e, ctx) { /* Live-Preview */ },
+    up(e, ctx) { /* Commit */ },
+    key(k, ctx) { /* return true = konsumiert (z. B. Enter) */ },
+    cancel(ctx) { /* ESC/Rechtsklick: Session-State zurücksetzen */ },
+  },
+};
+```
+
+### Kernregeln
+
+1. **Eine Aktion = eine `doc.transact(() => ...)`** = genau ein Undo-Schritt.
+2. **Session-State als Modul-Member** (nicht in `options` – diese sind geteilter UI-State).
+3. **`cancel` setzt den Session-State immer zurück.**
+4. **Koordinaten-Konventionen:** rect `x/y` = Zentrum der BBox; circle/arc `el.x/el.y` = Zentrum; Winkel in Grad (0° = 3 Uhr, CCW).
+5. **Undo-fähig schreiben** nur über `doc.addElement/updateElement/deleteElements`.
+
+## Bibliotheks-Provider (LibraryProviderExtension)
+
+```ts
+const myProvider: LibraryProviderExtension = {
+  id: 'my-catalog',
+  label: 'Mein Katalog',
+  async listFolders() { return [{ id: 'f1', label: 'Ordner', parentId: null }]; },
+  async listBlocks(folderId) { return [/* LibBlock[] */]; },
+  async getBlock(id) { return /* LibBlock */; },
+};
+```
+
+`LibBlock.payload` = JSON-String eines CADElement-Arrays → Drag&Drop
+in die Zeichenfläche funktioniert automatisch über den bestehenden
+Drop-Kanal. Thumbnail = eigenständiges SVG.
+
+## Registrierung
+
+Built-in-Plugins werden in `src/plugins/index.ts` per
+`pluginRegistry.registerV2(plugin)` registriert; `enabledByDefault`
+macht sie aktiv (alternativ per `pluginRegistry.enableV2(id)`).
+
+## Beispiel: Minimal-Plugin
+
+```ts
+// plugins/builtin/stamp/index.ts
+import type { PluginV2, ToolExtensionV2 } from '../../types';
+
+const stampTool: ToolExtensionV2 = {
+  manifest: {
+    id: 'stamp', label: 'Stempel', icon: '\u25c6',
+    ribbonTab: 'insert', tags: ['basic'],
+    description: 'Platziert ein Quadrat',
+  },
+  optionsSchema: [{ key: 'size', label: 'Größe', type: 'number', min: 10, max: 200 }],
+  handlers: {
+    down(e, ctx) {
+      const c = ctx as any;
+      if (!c.doc) return;
+      const size = (ctx.options.size as number | undefined) ?? 50;
+      c.doc.transact(() => c.doc.addElement({
+        id: `stamp_${Date.now()}`,
+        type: 'rect', layerId: 'layer-0',
+        x: e.world.x, y: e.world.y,
+        width: size, height: size,
+        properties: {},
+      }));
+      ctx.setStatus('Stempel platziert');
+    },
+  },
+};
+
+export const stampPlugin: PluginV2 = {
+  manifest: {
+    id: 'stamp', name: 'Stempel', version: '1.0.0', author: 'WebCAD',
+    description: 'Beispielplugin', category: 'elements', enabledByDefault: true,
+  },
+  tools: [stampTool],
+};
+```
+
+Registrieren in `src/plugins/index.ts`:
+
+```ts
+pluginRegistry.registerV2(stampPlugin);
+```

frontend/package-lock.json

@@ -10,6 +10,7 @@
       "dependencies": {
         "dxf-parser": "^1.1.2",
         "pdf-lib": "^1.17.1",
+        "pixi.js": "^8.20.1",
         "rbush": "^4.0.1",
         "react": "^18.3.1",
         "react-dom": "^18.3.1",
@@ -661,6 +662,11 @@
         "pako": "^1.0.10"
       }
     },
+    "node_modules/@pixi/colord": {
+      "version": "2.9.6",
+      "resolved": "https://registry.npmjs.org/@pixi/colord/-/colord-2.9.6.tgz",
+      "integrity": "sha512-nezytU2pw587fQstUu1AsJZDVEynjskwOL+kibwcdxsMBFqPsFFNA7xl0ii/gXuDi6M0xj3mfRJj8pBSc2jCfA=="
+    },
     "node_modules/@playwright/test": {
       "version": "1.62.0",
       "resolved": "https://registry.npmjs.org/@playwright/test/-/test-1.62.0.tgz",
@@ -1094,6 +1100,11 @@
       "integrity": "sha512-c9h9dVVMigMPc4bwTvC5dxqtqJZwQPePsWjPlpSOnojbor6pGqdk541lfA7AqFQr5pB1BRdq0juY9db81BwyFw==",
       "dev": true
     },
+    "node_modules/@types/earcut": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/@types/earcut/-/earcut-3.0.0.tgz",
+      "integrity": "sha512-k/9fOUGO39yd2sCjrbAJvGDEQvRwRnQIZlBz43roGwUZo5SHAmyVvSFyaVVZkicRVCaDXPKlbxrUcBuJoSWunQ=="
+    },
     "node_modules/@types/estree": {
       "version": "1.0.9",
       "resolved": "https://registry.npmjs.org/@types/estree/-/estree-1.0.9.tgz",
@@ -1257,6 +1268,19 @@
         "url": "https://opencollective.com/vitest"
       }
     },
+    "node_modules/@webgpu/types": {
+      "version": "0.1.72",
+      "resolved": "https://registry.npmjs.org/@webgpu/types/-/types-0.1.72.tgz",
+      "integrity": "sha512-0cF7RFM2edNoiIS1ODJp0/Gzv4/xSXhwoR0YCza+OWpJWtn4wmo9DvK91aLlH9+uUnwIriP7ZiC3WitmyhuzBw=="
+    },
+    "node_modules/@xmldom/xmldom": {
+      "version": "0.8.15",
+      "resolved": "https://registry.npmjs.org/@xmldom/xmldom/-/xmldom-0.8.15.tgz",
+      "integrity": "sha512-/5NV/vDALVFDXgLmfsy9TRCBlKwO2LNBFzpzvb9iIj+jR+eSc6DLYYvVOdivT/jm7MtU6TebYuRmzEOI7w40UA==",
+      "engines": {
+        "node": ">=10.0.0"
+      }
+    },
     "node_modules/abstract-leveldown": {
       "version": "6.2.3",
       "resolved": "https://registry.npmjs.org/abstract-leveldown/-/abstract-leveldown-6.2.3.tgz",
@@ -1559,6 +1583,11 @@
         "loglevel": "^1.7.1"
       }
     },
+    "node_modules/earcut": {
+      "version": "3.2.3",
+      "resolved": "https://registry.npmjs.org/earcut/-/earcut-3.2.3.tgz",
+      "integrity": "sha512-vnS4AVwp1KHAF13i1vp1/2D5evWy3k5u/iW/B81QVsUZtV8cv2tU0b2VNFlqvh4kYwrFMDdjPCfAmfyJW9y14Q=="
+    },
     "node_modules/electron-to-chromium": {
       "version": "1.5.378",
       "resolved": "https://registry.npmjs.org/electron-to-chromium/-/electron-to-chromium-1.5.378.tgz",
@@ -1629,6 +1658,11 @@
         "@types/estree": "^1.0.0"
       }
     },
+    "node_modules/eventemitter3": {
+      "version": "5.0.4",
+      "resolved": "https://registry.npmjs.org/eventemitter3/-/eventemitter3-5.0.4.tgz",
+      "integrity": "sha512-mlsTRyGaPBjPedk6Bvw+aqbsXDtoAyAzm5MO7JgU+yVRyMQ5O8bD4Kcci7BS85f93veegeCPkL8R4GLClnjLFw=="
+    },
     "node_modules/expect-type": {
       "version": "1.3.0",
       "resolved": "https://registry.npmjs.org/expect-type/-/expect-type-1.3.0.tgz",
@@ -1678,6 +1712,14 @@
         "node": ">=6.9.0"
       }
     },
+    "node_modules/gifuct-js": {
+      "version": "2.1.2",
+      "resolved": "https://registry.npmjs.org/gifuct-js/-/gifuct-js-2.1.2.tgz",
+      "integrity": "sha512-rI2asw77u0mGgwhV3qA+OEgYqaDn5UNqgs+Bx0FGwSpuqfYn+Ir6RQY5ENNQ8SbIiG/m5gVa7CD5RriO4f4Lsg==",
+      "dependencies": {
+        "js-binary-schema-parser": "^2.0.3"
+      }
+    },
     "node_modules/html-encoding-sniffer": {
       "version": "6.0.0",
       "resolved": "https://registry.npmjs.org/html-encoding-sniffer/-/html-encoding-sniffer-6.0.0.tgz",
@@ -1737,6 +1779,11 @@
       "integrity": "sha512-bCYeRA2rVibKZd+s2625gGnGF/t7DSqDs4dP7CrLA1m7jKWz6pps0LpYLJN8Q64HtmPKJ1hrN3nzPNKFEKOUiQ==",
       "dev": true
     },
+    "node_modules/ismobilejs": {
+      "version": "1.1.1",
+      "resolved": "https://registry.npmjs.org/ismobilejs/-/ismobilejs-1.1.1.tgz",
+      "integrity": "sha512-VaFW53yt8QO61k2WJui0dHf4SlL8lxBofUuUmwBo0ljPk0Drz2TiuDW4jo3wDcv41qy/SxrJ+VAzJ/qYqsmzRw=="
+    },
     "node_modules/isomorphic.js": {
       "version": "0.2.5",
       "resolved": "https://registry.npmjs.org/isomorphic.js/-/isomorphic.js-0.2.5.tgz",
@@ -1746,6 +1793,11 @@
         "url": "https://github.com/sponsors/dmonad"
       }
     },
+    "node_modules/js-binary-schema-parser": {
+      "version": "2.0.3",
+      "resolved": "https://registry.npmjs.org/js-binary-schema-parser/-/js-binary-schema-parser-2.0.3.tgz",
+      "integrity": "sha512-xezGJmOb4lk/M1ZZLTR/jaBHQ4gG/lqQnJqdIv4721DMggsa1bDVlHXNeHYogaIEHD9vCRv0fcL4hMA+Coarkg=="
+    },
     "node_modules/js-tokens": {
       "version": "4.0.0",
       "resolved": "https://registry.npmjs.org/js-tokens/-/js-tokens-4.0.0.tgz",
@@ -2377,6 +2429,11 @@
       "resolved": "https://registry.npmjs.org/pako/-/pako-1.0.11.tgz",
       "integrity": "sha512-4hLB8Py4zZce5s4yd9XzopqwVv/yGNhV1Bl8NTmCq1763HeK2+EwVTv+leGeL13Dnh2wfbqowVPXCIO0z4taYw=="
     },
+    "node_modules/parse-svg-path": {
+      "version": "0.2.0",
+      "resolved": "https://registry.npmjs.org/parse-svg-path/-/parse-svg-path-0.2.0.tgz",
+      "integrity": "sha512-Tf7FFIrguPKQwzD4pWnYkR2VOv3raoHeKED80Bm+BYHI3KxC8KsgsGC5+fSMzAGDA6UEk4bHvmi+RsjmL3khpg=="
+    },
     "node_modules/parse5": {
       "version": "8.0.1",
       "resolved": "https://registry.npmjs.org/parse5/-/parse5-8.0.1.tgz",
@@ -2424,6 +2481,27 @@
         "url": "https://github.com/sponsors/jonschlinkert"
       }
     },
+    "node_modules/pixi.js": {
+      "version": "8.20.1",
+      "resolved": "https://registry.npmjs.org/pixi.js/-/pixi.js-8.20.1.tgz",
+      "integrity": "sha512-akLVBMLvQbaEViqsmVraK0Njer1q4Q4lm4iNKuzvBiFrV8q+6/+HluJN3sWIwO663IBeQtUUS/CaXFJZs6ffXQ==",
+      "dependencies": {
+        "@pixi/colord": "^2.9.6",
+        "@types/earcut": "^3.0.0",
+        "@webgpu/types": "^0.1.69",
+        "@xmldom/xmldom": "^0.8.15",
+        "earcut": "^3.0.2",
+        "eventemitter3": "^5.0.1",
+        "gifuct-js": "^2.1.2",
+        "ismobilejs": "^1.1.1",
+        "parse-svg-path": "^0.2.0",
+        "tiny-lru": "^11.4.7"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/pixijs"
+      }
+    },
     "node_modules/playwright": {
       "version": "1.62.0",
       "resolved": "https://registry.npmjs.org/playwright/-/playwright-1.62.0.tgz",
@@ -2754,6 +2832,14 @@
       "integrity": "sha512-9QNk5KwDF+Bvz+PyObkmSYjI5ksVUYtjW7AU22r2NKcfLJcXp96hkDWU3+XndOsUb+AQ9QhfzfCT2O+CNWT5Tw==",
       "dev": true
     },
+    "node_modules/tiny-lru": {
+      "version": "11.4.7",
+      "resolved": "https://registry.npmjs.org/tiny-lru/-/tiny-lru-11.4.7.tgz",
+      "integrity": "sha512-w/Te7uMUVeH0CR8vZIjr+XiN41V+30lkDdK+NRIDCUYKKuL9VcmaUEmaPISuwGhLlrTGh5yu18lENtR9axSxYw==",
+      "engines": {
+        "node": ">=12"
+      }
+    },
     "node_modules/tinybench": {
       "version": "2.9.0",
       "resolved": "https://registry.npmjs.org/tinybench/-/tinybench-2.9.0.tgz",

frontend/package.json

@@ -9,11 +9,12 @@
     "preview": "vite preview",
     "test": "vitest run",
     "test:e2e": "playwright test",
-    "test:e2e:ci": "playwright test playwright-tests/diagnose-editor.test.ts playwright-tests/tool-exhaustive.test.ts"
+    "test:e2e:ci": "playwright test playwright-tests/diagnose-editor.test.ts playwright-tests/tool-exhaustive.test.ts playwright-tests/perf-gate.test.ts"
   },
   "dependencies": {
     "dxf-parser": "^1.1.2",
     "pdf-lib": "^1.17.1",
+    "pixi.js": "^8.20.1",
     "rbush": "^4.0.1",
     "react": "^18.3.1",
     "react-dom": "^18.3.1",

frontend/playwright-tests/perf-gate.test.ts

@@ -0,0 +1,90 @@
+/**
+ * Performance Gate (Task I1): 10.000 Interaktions-Budget.
+ * Erstellt ein Projekt mit Elementen, misst die Zeit fuer 10.000
+ * Canvas-Interaktionen ( dispatched pointer events ) und prueft
+ * dass sie innerhalb des Budgets liegen und keine JS-Fehler auftreten.
+ */
+import { test, expect, chromium } from '@playwright/test';
+
+const API_URL = process.env.API_URL || 'http://localhost:3001';
+const BASE_URL = process.env.FRONTEND_URL || 'http://localhost:5173';
+const N_INTERACTIONS = 10000;
+const BUDGET_MS = 15000; // 10k Interaktionen muessen in < 15s sein
+
+async function api(method: string, endpoint: string, body?: unknown, token?: string) {
+  const headers: Record<string, string> = { 'Content-Type': 'application/json' };
+  if (token) headers.Authorization = `Bearer ${token}`;
+  const res = await fetch(`${API_URL}${endpoint}`, {
+    method,
+    headers,
+    body: body ? JSON.stringify(body) : undefined,
+  });
+  return { status: res.status, body: await res.json() };
+}
+
+test('Perf Gate: 10k Canvas-Interaktionen im Budget, keine JS-Fehler', async () => {
+  test.setTimeout(180000);
+  const browser = await chromium.launch({ headless: true });
+  const page = await browser.newPage({ viewport: { width: 1600, height: 1000 } });
+  const jsErrors: string[] = [];
+  page.on('pageerror', (err) => jsErrors.push(String(err)));
+
+  const email = `perf-${Date.now()}@example.com`;
+  const reg = await api('POST', '/api/auth/register', { email, password: 'Test1234!', name: 'Perf' });
+  expect(reg.status).toBe(201);
+  const token = reg.body.session.token;
+
+  const proj = await api('POST', '/api/projects', { name: `Perf-${Date.now()}`, description: 'perf gate' }, token);
+  expect(proj.status).toBe(201);
+
+  await page.goto(`${BASE_URL}/`);
+  await page.evaluate((t) => localStorage.setItem('auth_token', t), token);
+  await page.reload();
+  await page.waitForSelector('.dashboard-project-card', { timeout: 30000 });
+  await page.locator('.dashboard-project-card').first().click();
+  await page.waitForSelector('canvas', { timeout: 30000 });
+  await page.waitForTimeout(2000); // Engines mounten
+
+  // Finde den Haupt-Canvas
+  const canvas = page.locator('canvas').first();
+  const box = await canvas.boundingBox();
+  expect(box).toBeTruthy();
+
+  // ── 10.000 Interaktionen ueber dispatched events (schnell, im Browser) ──
+  const elapsed = await page.evaluate(({ n, bx, by }) => {
+    const target = document.querySelector('canvas') as HTMLCanvasElement;
+    const startX = bx + 100;
+    const startY = by + 100;
+    const t0 = performance.now();
+    let x = startX, y = startY;
+    for (let i = 0; i < n; i++) {
+      x = startX + Math.sin(i * 0.01) * 300;
+      y = startY + Math.cos(i * 0.013) * 200;
+      target.dispatchEvent(new PointerEvent('pointermove', {
+        clientX: x, clientY: y, button: 0, buttons: 0,
+        pointerId: 1, pointerType: 'mouse',
+        bubbles: true, cancelable: true,
+      }));
+      if (i % 500 === 0) {
+        // Alle 500 auch ein down/up-Paar (Interaktionsmix)
+        target.dispatchEvent(new PointerEvent('pointerdown', {
+          clientX: x, clientY: y, button: 0, buttons: 1,
+          pointerId: 1, pointerType: 'mouse',
+          bubbles: true, cancelable: true,
+        }));
+        target.dispatchEvent(new PointerEvent('pointerup', {
+          clientX: x, clientY: y, button: 0, buttons: 0,
+          pointerId: 1, pointerType: 'mouse',
+          bubbles: true, cancelable: true,
+        }));
+      }
+    }
+    return performance.now() - t0;
+  }, { n: N_INTERACTIONS, bx: box!.x, by: box!.y });
+
+  console.log(`Perf Gate: ${N_INTERACTIONS} Interaktionen in ${elapsed.toFixed(0)}ms (Budget: ${BUDGET_MS}ms)`);
+  expect(elapsed).toBeLessThan(BUDGET_MS);
+  expect(jsErrors).toHaveLength(0);
+
+  await browser.close();
+});

frontend/playwright-tests/phase-a-verify.test.ts

@@ -0,0 +1,124 @@
+/**
+ * Phase-A-Verifikation (ROADMAP Übergabepunkt):
+ * Beweist mit echtem Chromium bei gesetzttem VITE_TOOL_DISPATCHER=v2:
+ * 1. Ribbon-V2-Sektion rendert die registrierten V2-Werkzeuge
+ * 2. Werkzeugwechsel über den v2tool:-Kanal funktioniert
+ * 3. Zeichnen + Ctrl+Z/Y laufen crashfrei durch den V2-Pfad
+ *
+ * Läuft gegen die bereits gestarteten Dev-Server (reuseExistingServer).
+ */
+import { test, expect, chromium } from '@playwright/test';
+
+const API_URL = process.env.API_URL || 'http://localhost:3001';
+const BASE_URL = process.env.FRONTEND_URL || 'http://localhost:5173';
+
+async function api(method: string, endpoint: string, body?: unknown, token?: string) {
+  const headers: Record<string, string> = { 'Content-Type': 'application/json' };
+  if (token) headers.Authorization = `Bearer ${token}`;
+  const res = await fetch(`${API_URL}${endpoint}`, {
+    method,
+    headers,
+    body: body ? JSON.stringify(body) : undefined,
+  });
+  return { status: res.status, body: await res.json() };
+}
+
+test('Phase-A: V2-Pfad end-to-end (Ribbon-Sektion, Toolwechsel, Zeichnen+Undo crashfrei)', async () => {
+  test.setTimeout(180000); // Summe aller Schritte (Auth+Nav+Pixi lazy+Draw+Undo+Shots)
+  const browser = await chromium.launch({ headless: true });
+  const page = await browser.newPage({ viewport: { width: 1600, height: 1000 } });
+
+  // ── Auth & Navigation (Muster aus diagnose-editor.test.ts) ──
+  const email = `pa-verify-${Date.now()}@example.com`;
+  const reg = await api('POST', '/api/auth/register', { email, password: 'Test1234!', name: 'PA' });
+  expect(reg.status).toBe(201);
+  const token = reg.body.session.token;
+
+  const proj = await api('POST', '/api/projects', { name: `PA-${Date.now()}`, description: 'x' }, token);
+  expect(proj.status).toBe(201);
+
+  await page.goto(`${BASE_URL}/`);
+  await page.evaluate((t) => localStorage.setItem('auth_token', t), token);
+  await page.reload();
+
+  // Dashboard-Karte warten (Klasse .dashboard-project-card existiert in Dashboard.tsx Z.688):
+  await page.waitForSelector('.dashboard-project-card', { timeout: 30000 });
+  await page.locator('.dashboard-project-card').first().click();
+  await page.waitForSelector('canvas', { timeout: 30000 });
+  await page.waitForTimeout(1500); // Engines mounten lassen
+
+  // ── Fehlerkanäle sammeln — V2-Pfad darf KEINE erzeugen ──
+  const pageErrors: string[] = [];
+  const consoleErrors: string[] = [];
+  page.on('pageerror', (err) => pageErrors.push(err.message));
+  page.on('console', (msg) => {
+    if (msg.type() === 'error') consoleErrors.push(msg.text());
+  });
+
+  // ── 1) Ribbon: Zeichenflächen-Tab öffnen und V2-Sektion prüfen ──
+  await page.locator('.ribbon-tab', { hasText: 'Zeichenfläche' }).first().click();
+  await page.waitForTimeout(300);
+
+  const v2Section = page.locator('text=V2:').first();
+  await expect(v2Section).toBeVisible();
+
+  // Registrierte V2-Buttons müssen vorhanden sein (alle Registry-Tools):
+  const v2ButtonGroup = page.locator('[data-v2tool]');
+  const buttonCount = await v2ButtonGroup.count();
+  expect(buttonCount).toBeGreaterThanOrEqual(22);
+
+  // ── 2) Toolwechsel: Linie über V2-Button aktivieren ──
+  await page.locator('[data-v2tool="line"]').first().click();
+  await page.waitForTimeout(300);
+
+  // ── 3) Zeichnen auf dem Canvas (Zug in der Mitte) ──
+  const canvas = page.locator('canvas').first();
+  const box = await canvas.boundingBox();
+  expect(box).not.toBeNull();
+  const cx = box!.x + box!.width / 2;
+  const cy = box!.y + box!.height / 2;
+
+  await page.mouse.move(cx - 100, cy - 50);
+  await page.mouse.down();
+  await page.mouse.move(cx + 100, cy + 50, { steps: 8 });
+  await page.mouse.up();
+  await page.waitForTimeout(400);
+
+  // ── 4) Undo/Redo Shortcuts crashfrei ──
+  await page.keyboard.press('Control+z');
+  await page.waitForTimeout(300);
+  await page.keyboard.press('Control+y');
+  await page.waitForTimeout(300);
+
+  // ── 4b) Task C4: PixiRenderer hat die Elemente im Cache ──
+  const pixiInfo = await page.evaluate(() => {
+    const debug = (window as unknown as { __v2Debug?: { info(): { cachedElements: number; ready: boolean } | null } }).__v2Debug;
+    return debug?.info() ?? null;
+  });
+  expect(pixiInfo).not.toBeNull();
+  expect(pixiInfo!.ready).toBe(true);
+  expect(pixiInfo!.cachedElements).toBeGreaterThanOrEqual(1);
+
+  // Nach Undo muss der Cache leer sein (Referenzdiff synchronisiert)
+  await page.keyboard.press('Control+z');
+  await page.waitForTimeout(300);
+  const pixiInfoAfterUndo = await page.evaluate(() => {
+    const debug = (window as unknown as { __v2Debug?: { info(): { cachedElements: number; ready: boolean } | null } }).__v2Debug;
+    return debug?.info() ?? null;
+  });
+  expect(pixiInfoAfterUndo!.cachedElements).toBe(0);
+
+  // Kein Seitenfehler durch den gesamten V2-Ablauf:
+  expect(pageErrors).toEqual([]);
+  // Konsolenfehler nur tolerieren, wenn sie nichts mit dem V2-Pfad zu tun haben:
+  const v2Related = consoleErrors.filter((e) => /dispatcher|v2tool|undo/i.test(e));
+  expect(v2Related).toEqual([]);
+
+  // ── 5) Sichtbelege ──
+  await page.screenshot({ path: 'playwright-tests/screenshots/phase-a-canvas.png', fullPage: false });
+  await page.keyboard.press('Control+z');
+  await page.waitForTimeout(250);
+  await page.screenshot({ path: 'playwright-tests/screenshots/phase-a-after-undo.png', fullPage: false });
+
+  await browser.close();
+});

frontend/src/App.tsx

@@ -15,9 +15,13 @@ import CanvasArea from './components/CanvasArea';
 import RightSidebar from './components/RightSidebar';
 import CommandLine from './components/CommandLine';
 import StatusBar from './components/StatusBar';
+import LayoutBar from './components/LayoutBar';
 import MobileDrawers from './components/MobileDrawers';
 import BackgroundImport from './components/BackgroundImport';
 import HistoryPanel from './components/HistoryPanel';
+import V2HistoryPanel from './components/V2HistoryPanel';
+import GuestPanel from './components/GuestPanel';
+import { V2_TOOLS_ENABLED } from './kernel/featureFlags';
 import SettingsModal from './components/SettingsModal';
 import InlineTextEditor from './components/InlineTextEditor';
 import { BackgroundService, type BackgroundConfig } from './services/backgroundService';
@@ -174,6 +178,7 @@ const CADEditor: React.FC<CADEditorProps> = ({ projectId, token, onNavigateBack
 
   // History panel
   const [historyPanelOpen, setHistoryPanelOpen] = useState(false);
+  const [guestPanelOpen, setGuestPanelOpen] = useState(false);
 
   // Export format selector (cross-browser replacement for nwsave)
   const [exportFormatOpen, setExportFormatOpen] = useState(false);
@@ -1146,6 +1151,16 @@ const CADEditor: React.FC<CADEditorProps> = ({ projectId, token, onNavigateBack
     // ─── Tools actions ───
     if (action === 'measure') { setActiveTool('dimension'); setCommandHistory((prev) => [...prev, { prefix: '·', text: 'Messwerkzeug aktiv', type: 'info' }]); return; }
     if (action === 'history') { setHistoryPanelOpen((prev) => !prev); return; }
+    if (action === 'guests') { setGuestPanelOpen((prev) => !prev); return; }
+
+    // ─── V2 tools (Task A4.13): 'v2tool:<id>' → aktives Tool umschalten. Der
+    // bestehende CanvasArea-Sync aus A4.1 routet es an den Dispatcher (Flag aktiv).
+    if (action.startsWith('v2tool:')) {
+      const toolId = action.slice('v2tool:'.length);
+      setActiveTool(toolId);
+      setCommandHistory((prev) => [...prev, { prefix: '·', text: `V2-Werkzeug aktiv: ${toolId}`, type: 'info' }]);
+      return;
+    }
 
     // ─── Background ───
     if (action === 'background-import') { setBgImportOpen(true); return; }
@@ -1563,6 +1578,11 @@ const CADEditor: React.FC<CADEditorProps> = ({ projectId, token, onNavigateBack
         activeTab={activeRibbonTab}
         onTabChange={setActiveRibbonTab}
         onAction={handleRibbonAction}
+        onIsV2ToolActive={(toolId: string) =>
+          V2_TOOLS_ENABLED &&
+          activeTool === toolId &&
+          !!pluginRegistry.getToolV2(toolId)
+        }
         canvasBgColor={canvasBgColor}
         gridColor={gridColor}
         rulerEnabled={rulerEnabled}
@@ -1685,6 +1705,7 @@ const CADEditor: React.FC<CADEditorProps> = ({ projectId, token, onNavigateBack
         history={commandHistory}
         onCommand={handleCommand}
       />
+      <LayoutBar />
       <StatusBar
         snapEnabled={snapEnabled}
         orthoEnabled={orthoEnabled}
@@ -1728,7 +1749,11 @@ const CADEditor: React.FC<CADEditorProps> = ({ projectId, token, onNavigateBack
         onApply={handleBgApply}
         backgroundService={bgServiceRef.current}
       />
-      {historyPanelOpen && (
+      {historyPanelOpen && (V2_TOOLS_ENABLED ? (
+        <V2HistoryPanel
+          onClose={() => setHistoryPanelOpen(false)}
+        />
+      ) : (
         <HistoryPanel
           entries={historyEntries}
           onJumpTo={(entryId: string) => {
@@ -1741,6 +1766,15 @@ const CADEditor: React.FC<CADEditorProps> = ({ projectId, token, onNavigateBack
           }}
           onClose={() => setHistoryPanelOpen(false)}
         />
+      ))}
+      {guestPanelOpen && drawingId && (
+        <div className="guest-panel-overlay" style={{ position: 'fixed', top: 60, right: 12, width: 300, maxHeight: '70vh', background: 'var(--bg-secondary, #1e1e2e)', color: 'var(--fg-primary, #e0e0e0)', border: '1px solid rgba(128,128,128,0.3)', borderRadius: 8, boxShadow: '0 4px 16px rgba(0,0,0,0.4)', zIndex: 1000, display: 'flex', flexDirection: 'column' }}>
+          <GuestPanel
+            token={token}
+            drawingId={drawingId}
+            onClose={() => setGuestPanelOpen(false)}
+          />
+        </div>
       )}
       {exportFormatOpen && (
         <div className="export-format-overlay" onClick={() => setExportFormatOpen(false)}>

frontend/src/canvas/RenderEngine.ts

@@ -50,6 +50,10 @@ export class RenderEngine {
   private snapPoints: SnapPoint[] = [];
   private activeSnapPoint: SnapPoint | null = null;
   private previewElement: CADElement | null = null;
+  /** Gecachtes Hintergrundbild (BUG-4-Fix): nur 1× pro backgroundSrc laden. */
+  private bgImage: HTMLImageElement | null = null;
+  /** src des zuletzt erfolgreich geladenen Hintergrundbilds. */
+  private bgSrcLoaded = '';
   private dpr = 1;
 
   constructor(
@@ -379,13 +383,30 @@ export class RenderEngine {
   }
 
   private drawBackground(): void {
-    // Background image rendering with transform
-    const img = new Image();
-    img.src = this.options.backgroundSrc!;
-    if (!img.complete) {
-      img.onload = () => this.render();
+    // Background image rendering with transform.
+    // BUG-4-Fix: Das Bild wird nur EINMAL pro backgroundSrc geladen und gecacht;
+    // vorher wurde pro Frame ein neues Image erzeugt (Flackern/Rerender-Schleife).
+    const src = this.options.backgroundSrc!;
+
+    // Quellwechsel: Cache invalidieren und neu laden
+    if (!this.bgImage || this.bgSrcLoaded !== src) {
+      const img = new Image();
+      img.onload = () => {
+        this.bgImage = img;
+        this.bgSrcLoaded = src;
+        this.render(); // einmalig nach erfolgreichem Laden neu zeichnen
+      };
+      img.src = src;
+      if (img.complete && img.naturalWidth > 0) {
+        // Bereits aus Browser-Cache verfügbar (z.B. dataURL)
+        this.bgImage = img;
+        this.bgSrcLoaded = src;
+      }
       return;
     }
+
+    // Gecachtes Bild zeichnen
+    const img = this.bgImage;
     this.ctx.save();
     this.ctx.globalAlpha = this.options.backgroundOpacity;
     const s = this.zoomPan.getScale();

frontend/src/canvas/SnapEngine.ts

@@ -104,6 +104,16 @@ export class SnapEngine {
       if (this.config.modes.has('nearest')) {
         this.collectNearest(el, worldX, worldY, tol, candidates);
       }
+      // ── Task D11: erweiterte Snaps ──
+      if (this.config.modes.has('quadrant')) {
+        this.collectQuadrant(el, worldX, worldY, tol, candidates);
+      }
+      if (this.config.modes.has('perpendicular') && refPoint) {
+        this.collectPerpendicular(el, worldX, worldY, refPoint, tol, candidates);
+      }
+      if (this.config.modes.has('tangent') && refPoint) {
+        this.collectTangent(el, worldX, worldY, refPoint, tol, candidates);
+      }
     }
 
     // Intersection snap (between pairs)
@@ -124,7 +134,8 @@ export class SnapEngine {
 
     // Priority: endpoint > intersection > center > midpoint > nearest > grid
     const priority: Record<string, number> = {
-      endpoint: 0, intersection: 1, center: 2, midpoint: 3, nearest: 4, grid: 5,
+      endpoint: 0, intersection: 1, center: 2, quadrant: 3, perpendicular: 4,
+      tangent: 5, midpoint: 6, nearest: 7, grid: 8,
     };
 
     // Find best within tolerance — prefer higher priority if distances are close
@@ -234,6 +245,79 @@ export class SnapEngine {
     }
   }
 
+  /** Task D11: Quadranten-Punkte bei Kreis/Bogen (0/90/180/270). */
+  private collectQuadrant(el: CADElement, wx: number, wy: number, tol: number, out: SnapPoint[]): void {
+    const check = (x: number, y: number) => {
+      const d = Math.sqrt((wx - x) ** 2 + (wy - y) ** 2);
+      if (d < tol) out.push({ x, y, type: 'quadrant' });
+    };
+    if (el.type === 'circle' || el.type === 'arc') {
+      const r = (el.properties as Record<string, unknown>).radius as number | undefined ?? el.width / 2;
+      check(el.x + r, el.y); // 0
+      check(el.x, el.y + r); // 90
+      check(el.x - r, el.y); // 180
+      check(el.x, el.y - r); // 270
+    }
+  }
+
+  /**
+   * Task D11: Perpendicular-Fußpunkt — der Punkt auf einem Segment,
+   * an dem die Verbindung zum refPoint SENKRECHT auf dem Segment steht.
+   */
+  private collectPerpendicular(
+    el: CADElement,
+    wx: number, wy: number,
+    refPoint: { x: number; y: number },
+    tol: number,
+    out: SnapPoint[],
+  ): void {
+    const p = el.properties as Record<string, unknown>;
+    const segs: Array<Array<{ x: number; y: number }>> = [];
+    if (
+      p.x1 !== undefined && p.y1 !== undefined &&
+      p.x2 !== undefined && p.y2 !== undefined
+    ) {
+      segs.push([{ x: p.x1 as number, y: p.y1 as number }, { x: p.x2 as number, y: p.y2 as number }]);
+    } else if (Array.isArray(p.points)) {
+      const pts = p.points as Array<{ x: number; y: number }>;
+      for (let i = 0; i < pts.length - 1; i++) segs.push([pts[i], pts[i + 1]]);
+    }
+    for (const [a, b] of segs) {
+      const foot = this.nearestOnSegment(refPoint.x, refPoint.y, a.x, a.y, b.x, b.y);
+      const d = Math.sqrt((wx - foot.x) ** 2 + (wy - foot.y) ** 2);
+      if (d < tol) out.push({ x: foot.x, y: foot.y, type: 'perpendicular' });
+    }
+  }
+
+  /**
+   * Task D11: Tangenten-Punkte — Berührpunkte der Tangenten vom
+   * refPoint an den Kreis (beide Lösungen, klassische Konstruktion
+   * über rechtwinkliges Dreieck: Winkel = acos(r/d)).
+   */
+  private collectTangent(
+    el: CADElement,
+    wx: number, wy: number,
+    refPoint: { x: number; y: number },
+    tol: number,
+    out: SnapPoint[],
+  ): void {
+    if (el.type !== 'circle' && el.type !== 'arc') return;
+    const r = ((el.properties as Record<string, unknown>).radius as number | undefined) ?? el.width / 2;
+    const dx = refPoint.x - el.x;
+    const dy = refPoint.y - el.y;
+    const d = Math.hypot(dx, dy);
+    // refPoint im Zentrum oder im Kreisinneren: keine reale Tangente
+    if (d <= r) return;
+    const baseAng = Math.atan2(dy, dx);
+    const halfAng = Math.acos(r / d);
+    for (const t of [baseAng + halfAng, baseAng - halfAng]) {
+      const px = el.x + r * Math.cos(t);
+      const py = el.y + r * Math.sin(t);
+      const dist = Math.sqrt((wx - px) ** 2 + (wy - py) ** 2);
+      if (dist < tol) out.push({ x: px, y: py, type: 'tangent' });
+    }
+  }
+
   private collectNearest(el: CADElement, wx: number, wy: number, tol: number, out: SnapPoint[]): void {
     const p = el.properties;
     const check = (x: number, y: number) => {
@@ -400,3 +484,13 @@ export class SnapEngine {
     return { x: snapX, y: snapY, type: 'nearest' };
   }
 }
+
+// ─────────────────────────────────────────────────────────────
+// Task D11: fromOffset — Basispunkt + Eingabefeld dx/dy.
+// Reine Funktion (für from-offset-Snap im UI nutzbar).
+// ─────────────────────────────────────────────────────────────
+
+/** Zielpunkt = Basispunkt + Offsets dx/dy (Task D11 from-offset). */
+export function fromOffset(base: { x: number; y: number }, dx: number, dy: number): { x: number; y: number } {
+  return { x: base.x + dx, y: base.y + dy };
+}

frontend/src/canvas/ZoomPanController.ts

@@ -60,6 +60,17 @@ export class ZoomPanController {
     this.offsetY = -minY * this.scale + padding;
   }
 
+  /**
+   * Setzt die Absolute Ansicht: Welt-Punkt `center` landet exakt im
+   * Canvas-Zentrum bei `scale` (Task G2 — Layout zoom-to).
+   */
+  setView(center: { x: number; y: number }, scale: number): void {
+    const s = Math.max(0.01, Math.min(100, scale));
+    this.scale = s;
+    this.offsetX = this.canvas.width / 2 - center.x * s;
+    this.offsetY = this.canvas.height / 2 - center.y * s;
+  }
+
   zoomToRect(rect: { minX: number; minY: number; maxX: number; maxY: number }): void {
     const padding = 20;
     const w = rect.maxX - rect.minX;

frontend/src/components/BlockLibraryTree.tsx

@@ -1,5 +1,6 @@
 import React, { useState, useEffect, useRef, useCallback } from 'react';
 import type { GlobalBlockFolder, GlobalBlock } from '../services/api';
+import { importSVGAsBlockPayload } from '../services/importService';
 import {
   getGlobalFolders,
   createGlobalFolder,
@@ -9,7 +10,15 @@ import {
   createGlobalBlock,
   renameGlobalBlock,
   deleteGlobalBlock,
+  setGlobalBlockFavorite,
+  exportLibrary,
+  importLibrary,
+  exportLibraryZip,
+  importLibraryZip,
 } from '../services/api';
+import { getActiveDocument } from '../kernel/document/documentService';
+import { generateBlockSvg } from '../utils/blockThumbnail';
+import type { CADElement } from '../types/cad.types';
 
 interface BlockLibraryTreeProps {
   token: string;
@@ -38,8 +47,23 @@ const BlockLibraryTree: React.FC<BlockLibraryTreeProps> = ({ token, onBlockDragS
   } | null>(null);
   const [loading, setLoading] = useState(true);
   const fileInputRef = useRef<HTMLInputElement>(null);
+  const wcadInputRef = useRef<HTMLInputElement>(null);
+  const zipInputRef = useRef<HTMLInputElement>(null);
   const [dragOverFolderId, setDragOverFolderId] = useState<string | null>(null);
 
+  // ─── Task F2: Suche, Favoriten, Thumbnail-Grid ───────────
+  const [searchQuery, setSearchQuery] = useState('');
+  const [viewMode, setViewMode] = useState<'tree' | 'grid'>('tree');
+
+  const handleToggleFavorite = useCallback(async (blockId: string, next: boolean) => {
+    try {
+      const updated = await setGlobalBlockFavorite(token, blockId, next);
+      setBlocks(prev => prev.map(b => (b.id === blockId ? { ...b, is_favorite: updated.is_favorite } : b)));
+    } catch {
+      // silently ignore — favorite stays unchanged on failure
+    }
+  }, [token]);
+
   const loadData = useCallback(async () => {
     try {
       const [allFolders, allBlocks] = await Promise.all([
@@ -59,6 +83,99 @@ const BlockLibraryTree: React.FC<BlockLibraryTreeProps> = ({ token, onBlockDragS
     loadData();
   }, [loadData]);
 
+  // ─── Task F3: Auswahl als Block speichern ─────────────────
+  const handleSaveSelectionAsBlock = useCallback(async () => {
+    const bridge = (window as unknown as { __v2GetSelection?: () => { ids: string[] } }).__v2GetSelection;
+    const ids = bridge?.().ids ?? [];
+    if (ids.length === 0) {
+      window.alert('Keine Auswahl im Canvas — erst Elemente wählen (V2-Tools).');
+      return;
+    }
+    const doc = getActiveDocument();
+    const elements: CADElement[] = [];
+    for (const id of ids) {
+      const el = doc?.getElement(id);
+      if (el) elements.push(el);
+    }
+    if (elements.length === 0) {
+      window.alert('Auswahl enthält keine Elemente.');
+      return;
+    }
+    const name = window.prompt('Blockname:', `Block-${new Date().toISOString().slice(0, 10)}`);
+    if (!name?.trim()) return;
+    try {
+      await createGlobalBlock(token, {
+        name: name.trim(),
+        block_data: JSON.stringify(elements),
+        svg_data: generateBlockSvg(elements),
+      });
+      await loadData();
+    } catch (err) {
+      window.alert(`Speichern fehlgeschlagen: ${err instanceof Error ? err.message : String(err)}`);
+    }
+  }, [token, loadData]);
+
+  // ─── Task F1: Library-Paket Export/Import ────────────────
+
+  const handleZipExport = useCallback(async () => {
+    try {
+      const blob = await exportLibraryZip(token);
+      const url = URL.createObjectURL(blob);
+      const a = document.createElement('a');
+      a.href = url;
+      a.download = `web-cad-library-${new Date().toISOString().slice(0, 10)}.wcadlib.zip`;
+      a.click();
+      URL.revokeObjectURL(url);
+    } catch (err) {
+      alert(`ZIP-Export fehlgeschlagen: ${err instanceof Error ? err.message : String(err)}`);
+    }
+  }, [token]);
+
+  const handleZipImport = useCallback(async (e: React.ChangeEvent<HTMLInputElement>) => {
+    const file = e.target.files?.[0];
+    if (!file) return;
+    try {
+      const result = await importLibraryZip(token, file);
+      alert(`Bibliothek importiert: ${result.imported_blocks} Blöcke, ${result.imported_folders} Ordner`);
+      await loadData();
+    } catch (err) {
+      alert(`ZIP-Import fehlgeschlagen: ${err instanceof Error ? err.message : String(err)}`);
+    } finally {
+      e.target.value = '';
+    }
+  }, [token, loadData]);
+
+  const handleLibraryExport = useCallback(async () => {
+    try {
+      const pkg = await exportLibrary(token);
+      const blob = new Blob([JSON.stringify(pkg, null, 2)], { type: 'application/json' });
+      const url = URL.createObjectURL(blob);
+      const a = document.createElement('a');
+      a.href = url;
+      a.download = `web-cad-library-${new Date().toISOString().slice(0, 10)}.wcadlib`;
+      a.click();
+      URL.revokeObjectURL(url);
+    } catch (err) {
+      alert(`Library-Export fehlgeschlagen: ${err instanceof Error ? err.message : String(err)}`);
+    }
+  }, [token]);
+
+  const handleWcadFile = useCallback(async (e: React.ChangeEvent<HTMLInputElement>) => {
+    const file = e.target.files?.[0];
+    if (!file) return;
+    try {
+      const text = await file.text();
+      const pkg = JSON.parse(text);
+      const result = await importLibrary(token, pkg);
+      alert(`Bibliothek importiert: ${result.imported_blocks} Blöcke, ${result.imported_folders} Ordner`);
+      await loadData();
+    } catch (err) {
+      alert(`Library-Import fehlgeschlagen: ${err instanceof Error ? err.message : String(err)}`);
+    } finally {
+      e.target.value = '';
+    }
+  }, [token, loadData]);
+
   // Build tree structure from flat lists
   const buildTree = useCallback((): FolderNode[] => {
     const folderMap = new Map<string, FolderNode>();
@@ -92,7 +209,10 @@ const BlockLibraryTree: React.FC<BlockLibraryTreeProps> = ({ token, onBlockDragS
     return roots;
   }, [folders, blocks, expandedIds]);
 
-  const rootBlocks = blocks.filter(b => !b.folder_id).sort((a, b) => a.name.localeCompare(b.name));
+  const q = searchQuery.toLowerCase().trim();
+  const matchesSearch = useCallback((b: GlobalBlock) => !q || b.name.toLowerCase().includes(q), [q]);
+  const rootBlocks = blocks.filter(b => !b.folder_id && matchesSearch(b)).sort((a, b) => a.name.localeCompare(b.name));
+  const favoriteBlocks = blocks.filter(b => b.is_favorite && matchesSearch(b)).sort((a, b) => a.name.localeCompare(b.name));
   const tree = buildTree();
 
   const toggleExpand = (folderId: string) => {
@@ -186,10 +306,11 @@ const BlockLibraryTree: React.FC<BlockLibraryTreeProps> = ({ token, onBlockDragS
         reader.onload = async (ev) => {
           const svgContent = ev.target?.result as string;
           try {
+            const svgPayload = importSVGAsBlockPayload(svgContent);
             const created = await createGlobalBlock(token, {
               name: file.name.replace(/\.svg$/i, ''),
               folder_id: folderId,
-              block_data: JSON.stringify({ type: 'svg', svg: svgContent }),
+              block_data: svgPayload.blockData ?? JSON.stringify({ type: 'svg', svg: svgContent }),
               svg_data: svgContent,
             });
             setBlocks(prev => [...prev, created]);
@@ -224,9 +345,10 @@ const BlockLibraryTree: React.FC<BlockLibraryTreeProps> = ({ token, onBlockDragS
     reader.onload = async (ev) => {
       const svgContent = ev.target?.result as string;
       try {
+        const svgPayload = importSVGAsBlockPayload(svgContent);
         const created = await createGlobalBlock(token, {
           name: file.name.replace(/\.svg$/i, ''),
-          block_data: JSON.stringify({ type: 'svg', svg: svgContent }),
+          block_data: svgPayload.blockData ?? JSON.stringify({ type: 'svg', svg: svgContent }),
           svg_data: svgContent,
         });
         setBlocks(prev => [...prev, created]);
@@ -271,6 +393,83 @@ const BlockLibraryTree: React.FC<BlockLibraryTreeProps> = ({ token, onBlockDragS
     setRenameValue('');
   };
 
+  // ─── Task F2: Block-Leaf mit Thumbnail + Favorite-Stern ──
+  const renderBlockLeaf = (block: GlobalBlock, depth: number): React.ReactNode => {
+    const isBlockRenaming = renamingId === block.id;
+    return (
+      <div
+        key={block.id}
+        className="tree-item tree-item-leaf draggable"
+        style={{ paddingLeft: `${depth * 16 + 8}px` }}
+        draggable
+        onDragStart={(e) => handleBlockDragStart(e, block)}
+        onContextMenu={(e) => handleContextMenu(e, 'block', block.id, block.folder_id)}
+        title={block.name}
+      >
+        {block.svg_data ? (
+          <span className="tree-thumb" dangerouslySetInnerHTML={{ __html: block.svg_data }} />
+        ) : (
+          <span className="tree-icon">📦</span>
+        )}
+        {isBlockRenaming ? (
+          <input
+            type="text"
+            className="tree-rename-input"
+            value={renameValue}
+            autoFocus
+            onChange={(e) => setRenameValue(e.target.value)}
+            onBlur={confirmRename}
+            onKeyDown={(e) => {
+              if (e.key === 'Enter') confirmRename();
+              if (e.key === 'Escape') { setRenamingId(null); setRenameValue(''); }
+            }}
+            onClick={(e) => e.stopPropagation()}
+          />
+        ) : (
+          <span
+            className="tree-label"
+            onDoubleClick={(e) => { e.stopPropagation(); startRename(block.id, block.name); }}
+          >
+            {block.name}
+          </span>
+        )}
+        <button
+          className={`tree-fav-btn${block.is_favorite ? ' active' : ''}`}
+          title={block.is_favorite ? 'Favorit entfernen' : 'Als Favorit markieren'}
+          onClick={(e) => { e.stopPropagation(); void handleToggleFavorite(block.id, !block.is_favorite); }}
+        >
+          {block.is_favorite ? '★' : '☆'}
+        </button>
+      </div>
+    );
+  };
+
+  // Task F2: Grid-Zelle mit Thumbnail
+  const renderGridCell = (block: GlobalBlock): React.ReactNode => (
+    <div
+      key={block.id}
+      className="lib-grid-cell"
+      draggable
+      onDragStart={(e) => handleBlockDragStart(e, block)}
+      onContextMenu={(e) => handleContextMenu(e, 'block', block.id, block.folder_id)}
+      title={`${block.name}${block.is_favorite ? ' ★' : ''}`}
+    >
+      <div className="lib-grid-thumb">
+        {block.svg_data
+          ? <span className="tree-thumb" dangerouslySetInnerHTML={{ __html: block.svg_data }} />
+          : <span className="lib-grid-placeholder">📦</span>}
+      </div>
+      <div className="lib-grid-name">{block.name}</div>
+      <button
+        className={`tree-fav-btn${block.is_favorite ? ' active' : ''}`}
+        title={block.is_favorite ? 'Favorit entfernen' : 'Als Favorit markieren'}
+        onClick={(e) => { e.stopPropagation(); void handleToggleFavorite(block.id, !block.is_favorite); }}
+      >
+        {block.is_favorite ? '★' : '☆'}
+      </button>
+    </div>
+  );
+
   const renderFolderNode = (node: FolderNode, depth: number): React.ReactNode => {
     const isRenaming = renamingId === node.folder.id;
     const isDragOver = dragOverFolderId === node.folder.id;
@@ -314,44 +513,7 @@ const BlockLibraryTree: React.FC<BlockLibraryTreeProps> = ({ token, onBlockDragS
         {node.expanded && (
           <div className="tree-children">
             {node.children.map(child => renderFolderNode(child, depth + 1))}
-            {node.blocks.map(block => {
-              const isBlockRenaming = renamingId === block.id;
-              return (
-                <div
-                  key={block.id}
-                  className="tree-item tree-item-leaf draggable"
-                  style={{ paddingLeft: `${(depth + 1) * 16 + 8}px` }}
-                  draggable
-                  onDragStart={(e) => handleBlockDragStart(e, block)}
-                  onContextMenu={(e) => handleContextMenu(e, 'block', block.id, block.folder_id)}
-                  title={block.name}
-                >
-                  <span className="tree-icon">📦</span>
-                  {isBlockRenaming ? (
-                    <input
-                      type="text"
-                      className="tree-rename-input"
-                      value={renameValue}
-                      autoFocus
-                      onChange={(e) => setRenameValue(e.target.value)}
-                      onBlur={confirmRename}
-                      onKeyDown={(e) => {
-                        if (e.key === 'Enter') confirmRename();
-                        if (e.key === 'Escape') { setRenamingId(null); setRenameValue(''); }
-                      }}
-                      onClick={(e) => e.stopPropagation()}
-                    />
-                  ) : (
-                    <span
-                      className="tree-label"
-                      onDoubleClick={(e) => { e.stopPropagation(); startRename(block.id, block.name); }}
-                    >
-                      {block.name}
-                    </span>
-                  )}
-                </div>
-              );
-            })}
+            {node.blocks.filter(matchesSearch).map(block => renderBlockLeaf(block, depth + 1))}
           </div>
         )}
       </div>
@@ -366,6 +528,41 @@ const BlockLibraryTree: React.FC<BlockLibraryTreeProps> = ({ token, onBlockDragS
     <div className="global-lib-tree" onContextMenu={(e) => handleContextMenu(e, 'root', null, null)}>
       <div className="global-lib-header">
         <span className="global-lib-title">🌐 Globale Bibliothek</span>
+        <button
+          className="global-lib-add-btn"
+          title="Canvas-Auswahl als Block speichern (F3)"
+          onClick={() => void handleSaveSelectionAsBlock()}
+        >
+          💾
+        </button>
+        <button
+          className="global-lib-add-btn"
+          title="Bibliothek als .wcadlib exportieren"
+          onClick={() => void handleLibraryExport()}
+        >
+          <svg viewBox="0 0 24 24" width="14" height="14" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round"><path d="M21 15v4a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v-4"/><polyline points="7 10 12 17 17 8"/><line x1="12" y1="3" x2="12" y2="15"/></svg>
+        </button>
+        <button
+          className="global-lib-add-btn"
+          title=".wcadlib-Bibliothek importieren"
+          onClick={() => wcadInputRef.current?.click()}
+        >
+          <svg viewBox="0 0 24 24" width="14" height="14" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round"><path d="M21 15v4a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v-4"/><polyline points="7 10 12 15 17 10"/><line x1="12" y1="15" x2="12" y2="3"/></svg>
+        </button>
+        <button
+          className="global-lib-add-btn"
+          title="Bibliothek als ZIP-Paket exportieren (Task F7)"
+          onClick={handleZipExport}
+        >
+          <svg viewBox="0 0 24 24" width="14" height="14" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round"><path d="M21 8v13H3V8"/><rect x="1" y="3" width="22" height="5"/><path d="M10 12h4"/></svg>
+        </button>
+        <button
+          className="global-lib-add-btn"
+          title=".wcadlib-ZIP-Paket importieren (Task F7)"
+          onClick={() => zipInputRef.current?.click()}
+        >
+          <svg viewBox="0 0 24 24" width="14" height="14" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round"><path d="M21 8v13H3V8"/><rect x="1" y="3" width="22" height="5"/><path d="M15 12l-3-3-3 3"/><path d="M12 9v8"/></svg>
+        </button>
         <button
           className="global-lib-add-btn"
           title="SVG in globale Bibliothek importieren"
@@ -374,45 +571,48 @@ const BlockLibraryTree: React.FC<BlockLibraryTreeProps> = ({ token, onBlockDragS
           <svg viewBox="0 0 24 24" width="14" height="14" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round"><path d="M21 15v4a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v-4"/><polyline points="17 8 12 3 7 8"/><line x1="12" y1="3" x2="12" y2="15"/></svg>
         </button>
         <input ref={fileInputRef} type="file" accept=".svg,image/svg+xml" style={{ display: 'none' }} onChange={handleSvgImport} />
+        <input ref={wcadInputRef} type="file" accept=".wcadlib,application/json" style={{ display: 'none' }} onChange={handleWcadFile} />
+        <input
+          type="file"
+          accept=".zip,.wcadlib.zip,application/zip"
+          ref={zipInputRef}
+          style={{ display: 'none' }}
+          onChange={handleZipImport}
+        />
+      </div>
+      <div className="global-lib-toolbar">
+        <input
+          type="text"
+          className="global-lib-search"
+          placeholder="Blöcke suchen…"
+          value={searchQuery}
+          onChange={(e) => setSearchQuery(e.target.value)}
+        />
+        <button
+          className="global-lib-add-btn"
+          title={viewMode === 'grid' ? 'Baumansicht' : 'Rasteransicht'}
+          onClick={() => setViewMode(m => (m === 'grid' ? 'tree' : 'grid'))}
+        >
+          {viewMode === 'grid' ? '☰' : '▦'}
+        </button>
       </div>
       <div className="tree tree-global" role="tree" aria-label="Globale Block-Bibliothek">
-        {tree.map(node => renderFolderNode(node, 0))}
-        {rootBlocks.map(block => {
-          const isBlockRenaming = renamingId === block.id;
-          return (
-            <div
-              key={block.id}
-              className="tree-item tree-item-leaf draggable"
-              draggable
-              onDragStart={(e) => handleBlockDragStart(e, block)}
-              onContextMenu={(e) => handleContextMenu(e, 'block', block.id, null)}
-              title={block.name}
-            >
-              <span className="tree-icon">📦</span>
-              {isBlockRenaming ? (
-                <input
-                  type="text"
-                  className="tree-rename-input"
-                  value={renameValue}
-                  autoFocus
-                  onChange={(e) => setRenameValue(e.target.value)}
-                  onBlur={confirmRename}
-                  onKeyDown={(e) => {
-                    if (e.key === 'Enter') confirmRename();
-                    if (e.key === 'Escape') { setRenamingId(null); setRenameValue(''); }
-                  }}
-                />
-              ) : (
-                <span
-                  className="tree-label"
-                  onDoubleClick={(e) => { e.stopPropagation(); startRename(block.id, block.name); }}
-                >
-                  {block.name}
-                </span>
-              )}
-            </div>
-          );
-        })}
+        {favoriteBlocks.length > 0 && (
+          <div className="lib-fav-section">
+            <div className="lib-fav-title">★ Favoriten</div>
+            {favoriteBlocks.map(block => renderBlockLeaf(block, 0))}
+          </div>
+        )}
+        {viewMode === 'grid' ? (
+          <div className="lib-grid">
+            {[...favoriteBlocks, ...blocks.filter(b => !b.is_favorite && matchesSearch(b)).sort((a, b) => a.name.localeCompare(b.name))].map(renderGridCell)}
+          </div>
+        ) : (
+          <>
+            {tree.map(node => renderFolderNode(node, 0))}
+            {rootBlocks.map(block => renderBlockLeaf(block, 0))}
+          </>
+        )}
         {folders.length === 0 && blocks.length === 0 && (
           <div className="global-lib-empty">Globale Bibliothek ist leer — Rechtsklick für Ordner</div>
         )}

frontend/src/components/CanvasArea.tsx

@@ -12,6 +12,14 @@ import { SpatialIndex } from '../canvas/SpatialIndex';
 import { LayerManager } from '../canvas/LayerManager';
 import { GroupManager } from '../tools/modification/GroupTool';
 import { formatCoordinate } from '../utils/format';
+import { InteractionDispatcher } from '../interaction/dispatcher';
+import { logger } from '../utils/logger';
+import { CADDocument } from '../kernel/document/CADDocument';
+import { YjsDocument } from '../crdt/YjsDocument';
+import { setActiveDocument, getActiveDocument } from '../kernel/document/documentService';
+import { V2_TOOLS_ENABLED, USE_PIXI_RENDERER } from '../kernel/featureFlags';
+import { PixiRenderer } from '../render/pixi/PixiRenderer';
+import { pluginRegistry } from '../plugins';
 
 const CanvasArea: React.FC<CanvasAreaProps> = ({
   cursorPos, viewMode, onViewChange, gridEnabled, orthoEnabled, snapEnabled,
@@ -26,6 +34,13 @@ const CanvasArea: React.FC<CanvasAreaProps> = ({
   const zoomPanRef = useRef<ZoomPanController | null>(null);
   const renderEngineRef = useRef<RenderEngine | null>(null);
   const interactionRef = useRef<InteractionEngine | null>(null);
+  const dispatcherRef = useRef<InteractionDispatcher | null>(null);
+  /** Task C2: PixiJS-Canvas-Ref für V2-Elemente-Overlay. */
+  const pixiCanvasRef = useRef<HTMLCanvasElement>(null);
+  /** Task C2: Aktiver PixiJS-Renderer (für Cleanup). */
+  const pixiRendererRef = useRef<PixiRenderer | null>(null);
+  /** Bereits an onElementCreated gemeldete V2-Element-IDs (verhindert Doppelmeldung bei jedem onChanged-Frame). */
+  const announcedV2Ids = useRef<Set<string>>(new Set());
   const spatialIndexRef = useRef<SpatialIndex | null>(null);
   const layerManagerRef = useRef<LayerManager | null>(null);
   const selectionEngineRef = useRef<SelectionEngine | null>(null);
@@ -44,6 +59,149 @@ const CanvasArea: React.FC<CanvasAreaProps> = ({
       canvas, zoomPan, renderEngine, snapEngine, selectionEngine, spatialIndex, layerManager,
     );
 
+    // ── Task A2/A4.14: V2-Pfad ist seit Verifikation STANDARD — Opt-out via
+    // VITE_TOOL_DISPATCHER=legacy. Siehe kernel/featureFlags.ts.
+    if (V2_TOOLS_ENABLED) {
+      const ydoc = new YjsDocument();
+      ydoc.data.layers.set('layer-0', {
+        id: 'layer-0', name: 'Standard', visible: true, locked: false,
+        color: '#ffffff', lineType: 'solid', transparency: 0, sortOrder: 0, parentId: null,
+      } as never);
+      const v2Doc = new CADDocument(ydoc);
+      // App-Level-Zugriffspunkt für HistoryPanel/Tastenkürzel (Task A4.11):
+      setActiveDocument(v2Doc);
+
+      // ── Task C2/C4: PixiJS-Renderer parallel schalten ──
+      // DEFENSIV: Ein Ausfall von Pixi (z.B. WebGL im Headless-Browser)
+      // darf NIEMALS den kompletten Editor-Mount brechen. Im Fehlerfall
+      // läuft weiter ohne Overlay.
+      let pixi: PixiRenderer | null = null;
+      const pixiCanvas = pixiCanvasRef.current;
+      if (pixiCanvas && USE_PIXI_RENDERER) {
+        try {
+          pixi = new PixiRenderer();
+          pixiRendererRef.current = pixi;
+          pixi.init(pixiCanvas);
+          pixi.waitForReady().then(() => {
+            // Task C4: Debug-Hook für Playwright-E2E-Assertions
+            (window as unknown as { __v2Debug: unknown }).__v2Debug = {
+              renderer: pixi,
+              info: () => pixiRendererRef.current?.getDebugInfo() ?? null,
+            };
+          }).catch((err) => {
+            logger.warn('Pixi init failed — V2-Overlay deaktiviert:', err);
+            pixi = null;
+            pixiRendererRef.current = null;
+          });
+        } catch (err) {
+          logger.warn('Pixi init exception — V2-Overlay deaktiviert:', err);
+          pixi = null;
+          pixiRendererRef.current = null;
+        }
+      }
+      /** Letztes bekanntes Elementobjekt je ID (Referenzdiff statt JSON). */
+      const lastKnownEl = new Map<string, CADElement>();
+      const syncPixi = (): void => {
+        if (!pixi) return;
+        void pixi.waitForReady().then(() => {
+          const all = v2Doc.getAllElements();
+          const visibleIds = new Set<string>();
+          for (const el of all) {
+            visibleIds.add(el.id);
+            // Nur neu zeichnen wenn sich die OBJEKTREFERENZ geändert hat:
+            if (lastKnownEl.get(el.id) !== el) {
+              lastKnownEl.set(el.id, el);
+              pixi!.drawElement(el, {
+                id: 'layer-0', name: 'Standard', visible: true, locked: false,
+                color: '#ffffff', lineType: 'solid', transparency: 0,
+                sortOrder: 0, parentId: null,
+              } as never, {
+                color: '#ffffff', lineType: 'solid', transparency: 0, visible: true,
+              });
+            }
+          }
+          // Gelöschte IDs aus dem Renderer entfernen:
+          for (const knownId of lastKnownEl.keys()) {
+            if (!visibleIds.has(knownId)) {
+              lastKnownEl.delete(knownId);
+              pixi!.removeElement(knownId);
+            }
+          }
+        });
+      };
+
+      // Committete V2-Elemente fließen über den etablierten Kanal in UI/State:
+      v2Doc.onChanged(() => {
+        for (const el of v2Doc.getAllElements()) {
+          if (!announcedV2Ids.current.has(el.id)) {
+            announcedV2Ids.current.add(el.id);
+            onElementCreated(el);
+          }
+        }
+        syncPixi();  // Task C2: V2-Elemente in den PixiJS-Overlay-Renderer spiegeln
+      });
+
+      dispatcherRef.current = new InteractionDispatcher(canvas, {
+        zoomPan,
+        setStatus: (msg) => {
+          /* StatusBar-Bridge folgt in A4 */
+        },
+        setPreview: (el) => renderEngine.setPreviewElement(el as CADElement | null),
+        getDoc: () => v2Doc,
+        getSelectionBridge: () => ({
+          getIds: () => Array.from(selectionEngine.getSelectedIds()),
+          setIds: (ids) => selectionEngine.selectByIds(ids, false),
+          hitTest: (wx, wy, tol) => renderEngine.hitTest(wx, wy, tol),
+        }),
+      });
+
+      // ── Task G2: Layout-Bridge für LayoutBar (zoom-to + Viewport-Save) ──
+      (window as unknown as { __v2LayoutBridge: unknown }).__v2LayoutBridge = {
+        zoomTo: (center: { x: number; y: number }, scale: number) => {
+          zoomPan.setView(center, scale);
+          renderEngineRef.current?.render();
+        },
+        getView: () => {
+          const vp = zoomPan.getViewport();
+          return {
+            center: { x: (vp.minX + vp.maxX) / 2, y: (vp.minY + vp.maxY) / 2 },
+            scale: zoomPan.getScale(),
+          };
+        },
+      };
+
+      // ── Task E6b: Selection-Bridge für GuestPanel (Stuhl-Zuweisung) ──
+      (window as unknown as { __v2GetSelection: unknown }).__v2GetSelection = () => {
+        const ids = Array.from(selectionEngine.getSelectedIds());
+        return { ids };
+      };
+
+      // ── Task C3fin: Snap-Marks + Selection-Handles im Pixi-Overlay ──
+      if (pixi && USE_PIXI_RENDERER) {
+        // Snap-Marks bei Mausbewegung (wenn ein V2-Tool aktiv ist):
+        const snapMove = (e: PointerEvent) => {
+          if (!dispatcherRef.current?.getActive()) return;
+          const rect = canvas.getBoundingClientRect();
+          const world = zoomPan.screenToWorld(e.clientX - rect.left, e.clientY - rect.top);
+          const snapResult = snapEngine.snap(world.x, world.y);
+          const marks = snapResult.point
+            ? [{ x: snapResult.point.x, y: snapResult.point.y, type: (snapResult.point as { type?: string }).type ?? 'snap' }]
+            : [];
+          pixi!.setSnapPoints(marks);
+        };
+        canvas.addEventListener('pointermove', snapMove);
+
+        // Selection-Handles bei Änderung:
+        const origSetIds = selectionEngine.selectByIds.bind(selectionEngine);
+        selectionEngine.selectByIds = (ids: string[], additive: boolean) => {
+          origSetIds(ids, additive);
+          const selected = v2Doc.getAllElements().filter((el) => ids.includes(el.id));
+          pixi!.setSelection({ selectedIds: ids, elements: selected });
+        };
+      }
+      logger.info('InteractionDispatcher v2 aktiviert (VITE_TOOL_DISPATCHER=v2)');
+    }
+
     zoomPanRef.current = zoomPan;
     renderEngineRef.current = renderEngine;
     interactionRef.current = interaction;
@@ -66,6 +224,11 @@ const CanvasArea: React.FC<CanvasAreaProps> = ({
 
     return () => {
       interaction.detach();
+      dispatcherRef.current?.destroy();
+      dispatcherRef.current = null;
+      pixiRendererRef.current?.destroy();   // Task C2: WebGL-Kontext freigeben
+      pixiRendererRef.current = null;
+      setActiveDocument(null);
       zoomPanRef.current = null;
       renderEngineRef.current = null;
       interactionRef.current = null;
@@ -229,9 +392,34 @@ const CanvasArea: React.FC<CanvasAreaProps> = ({
     const interaction = interactionRef.current;
     if (!interaction) return;
     interaction.setTool(activeTool as ToolType);
+    // Task A4.1: V2-Werkzeuge zusätzlich an den Dispatcher routen (Flag aktiv).
+    // Legacy bleibt parallel aktiv für noch nicht migrierte Tools.
+    dispatcherRef.current?.setActive(
+      pluginRegistry.getToolV2(activeTool) ? activeTool : null,
+    );
   // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [activeTool]);
 
+  // Task A4.11: Globale Undo/Redo-Shortcuts wirken nur auf das V2-Dokument,
+  // wenn es registriert ist (= Flag aktiv). Legacy-History bleibt unberührt.
+  useEffect(() => {
+    const onKey = (e: KeyboardEvent) => {
+      if (!(e.ctrlKey || e.metaKey)) return;
+      const doc = getActiveDocument();
+      if (!doc) return; // Flag aus → Legacy-Verhalten unangetastet
+      const key = e.key.toLowerCase();
+      if (key === 'z' && !e.shiftKey) {
+        e.preventDefault();
+        if (doc.undo()) logger.info('V2 undo');
+      } else if (key === 'y' || (key === 'z' && e.shiftKey)) {
+        e.preventDefault();
+        if (doc.redo()) logger.info('V2 redo');
+      }
+    };
+    window.addEventListener('keydown', onKey);
+    return () => window.removeEventListener('keydown', onKey);
+  }, []);
+
   // Sync selected template to interaction engine
   useEffect(() => {
     const interaction = interactionRef.current;
@@ -338,6 +526,22 @@ const CanvasArea: React.FC<CanvasAreaProps> = ({
         <span style={{ color: 'var(--color-text-faint)' }}>{unit}</span>
       </div>
 
+      {/* Task C2-Integration: PixiJS-Overlay für V2-Elemente — liegt ÜBER dem
+          Legacy-Canvas (z-index höher), rendert nur Elemente aus dem V2-Dokument.
+          Pointer-Events gehen durch (pointerEvents:none), damit Drag/Drop weiter
+          auf dem Legacy-Canvas funktioniert. */}
+      {V2_TOOLS_ENABLED && (
+        <canvas
+          ref={pixiCanvasRef}
+          style={{
+            position: 'absolute',
+            inset: 0,
+            pointerEvents: 'none',
+            zIndex: 5,
+          }}
+        />
+      )}
+
       <canvas
         ref={canvasRef}
         className="canvas-svg"

frontend/src/components/CommandLine.tsx

@@ -1,6 +1,7 @@
 import React, { useState, useRef, useMemo, useEffect } from 'react';
 import type { CommandLineProps } from '../types/ui.types';
 import { getCommandRegistry, type CommandDefinition } from '../services/commandRegistry';
+import { useUIMode } from '../services/uiModeService';
 
 const defaultHistory = [
   { prefix: '·' as const, text: 'Bereit · Werkzeug: Auswahl · 110 Objekte · 5 Ebenen', type: 'info' as const },
@@ -20,6 +21,9 @@ const categoryColors: Record<string, string> = {
 };
 
 const CommandLine: React.FC<CommandLineProps> = ({ history, onCommand }) => {
+  const uiMode = useUIMode();
+  if (uiMode === 'simple') return null;
+
   const [input, setInput] = useState('');
   const [selectedSuggestion, setSelectedSuggestion] = useState(0);
   const [commandHistory, setCommandHistory] = useState<string[]>([]);

frontend/src/components/GuestPanel.tsx

@@ -0,0 +1,170 @@
+/**
+ * GuestPanel (Task E6) — Gäste-Verwaltung für Event-Bestuhlung.
+ * Liste + Suche + Hinzufügen + Löschen. Zuweisung: seat_element_id
+ * wird per API gesetzt (Klick auf Stuhl im Canvas folgt in E6b).
+ */
+import React, { useState, useEffect, useCallback } from 'react';
+import { listGuests, createGuest, deleteGuest, updateGuest, type Guest } from '../services/api';
+
+/** E6b: Liest die erste Canvas-Auswahl (via CanvasArea-Bridge). */
+function getFirstSelectedId(): string | null {
+  const bridge = (window as unknown as { __v2GetSelection?: () => { ids: string[] } }).__v2GetSelection;
+  const ids = bridge?.().ids ?? [];
+  return ids[0] ?? null;
+}
+
+interface GuestPanelProps {
+  token: string;
+  drawingId: string;
+  onClose?: () => void;
+}
+
+const GuestPanel: React.FC<GuestPanelProps> = ({ token, drawingId, onClose }) => {
+  const [guests, setGuests] = useState<Guest[]>([]);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+  const [search, setSearch] = useState('');
+  const [newName, setNewName] = useState('');
+  const [newEmail, setNewEmail] = useState('');
+  const [newCategory, setNewCategory] = useState('standard');
+
+  const refresh = useCallback(async () => {
+    try {
+      setLoading(true);
+      setGuests(await listGuests(token, drawingId));
+      setError(null);
+    } catch (e) {
+      setError(e instanceof Error ? e.message : 'Fehler beim Laden');
+    } finally {
+      setLoading(false);
+    }
+  }, [token, drawingId]);
+
+  useEffect(() => {
+    void refresh();
+  }, [refresh]);
+
+  const handleAdd = async () => {
+    if (newName.trim() === '') return;
+    try {
+      await createGuest(token, drawingId, { name: newName.trim(), email: newEmail.trim() || undefined, category: newCategory });
+      setNewName('');
+      setNewEmail('');
+      setNewCategory('standard');
+      await refresh();
+    } catch (e) {
+      setError(e instanceof Error ? e.message : 'Fehler beim Hinzufügen');
+    }
+  };
+
+  const handleDelete = async (id: string) => {
+    try {
+      await deleteGuest(token, id);
+      await refresh();
+    } catch (e) {
+      setError(e instanceof Error ? e.message : 'Fehler beim Löschen');
+    }
+  };
+
+  const handleAssign = async (g: Guest) => {
+    try {
+      if (g.seat_element_id) {
+        await updateGuest(token, g.id, { seat_element_id: '' });
+      } else {
+        const seatId = getFirstSelectedId();
+        if (!seatId) {
+          setError('Erst einen Stuhl im Canvas auswählen.');
+          return;
+        }
+        await updateGuest(token, g.id, { seat_element_id: seatId });
+      }
+      await refresh();
+    } catch (e) {
+      setError(e instanceof Error ? e.message : 'Fehler bei Zuweisung');
+    }
+  };
+
+  const filtered = guests.filter((g) =>
+    g.name.toLowerCase().includes(search.toLowerCase()) ||
+    (g.email ?? '').toLowerCase().includes(search.toLowerCase())
+  );
+  const assigned = guests.filter((g) => g.seat_element_id).length;
+
+  return (
+    <div className="guest-panel" style={{ padding: 8, display: 'flex', flexDirection: 'column', gap: 8 }}>
+      <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center' }}>
+        <strong>Gäste ({guests.length})</strong>
+        <span style={{ fontSize: 12, opacity: 0.7 }}>{assigned} zugewiesen</span>
+        {onClose && <button onClick={onClose} aria-label="Schließen">×</button>}
+      </div>
+
+      <input
+        type="search"
+        placeholder="Suchen…"
+        value={search}
+        onChange={(e) => setSearch(e.target.value)}
+        style={{ padding: '4px 8px' }}
+      />
+
+      <div style={{ display: 'flex', gap: 4 }}>
+        <input
+          placeholder="Name"
+          value={newName}
+          onChange={(e) => setNewName(e.target.value)}
+          onKeyDown={(e) => { if (e.key === 'Enter') void handleAdd(); }}
+          style={{ flex: 1, padding: '4px 8px' }}
+        />
+        <input
+          placeholder="E-Mail (optional)"
+          value={newEmail}
+          onChange={(e) => setNewEmail(e.target.value)}
+          style={{ flex: 1, padding: '4px 8px' }}
+        />
+        <select value={newCategory} onChange={(e) => setNewCategory(e.target.value)} style={{ width: 90 }}>
+          <option value="standard">Standard</option>
+          <option value="vip">VIP</option>
+          <option value="staff">Staff</option>
+        </select>
+        <button onClick={() => void handleAdd()} disabled={newName.trim() === ''}>+</button>
+      </div>
+
+      {error && <div style={{ color: '#e5484d', fontSize: 12 }}>{error}</div>}
+      {loading && <div style={{ opacity: 0.6 }}>Lädt…</div>}
+
+      <ul style={{ listStyle: 'none', margin: 0, padding: 0, overflowY: 'auto', flex: 1 }}>
+        {filtered.map((g) => (
+          <li
+            key={g.id}
+            style={{
+              display: 'flex', justifyContent: 'space-between', alignItems: 'center',
+              padding: '6px 8px', borderBottom: '1px solid rgba(128,128,128,0.2)',
+            }}
+          >
+            <div>
+              <div style={{ fontWeight: g.category === 'vip' ? 700 : 400 }}>
+                {g.category === 'vip' ? '★ ' : ''}{g.name}
+              </div>
+              {g.email && <div style={{ fontSize: 11, opacity: 0.6 }}>{g.email}</div>}
+            </div>
+            <div style={{ display: 'flex', gap: 6, alignItems: 'center' }}>
+              <button
+                onClick={() => void handleAssign(g)}
+                title={g.seat_element_id ? 'Zuweisung aufheben' : 'Erste Canvas-Auswahl als Sitzplatz zuweisen'}
+                style={{ opacity: g.seat_element_id ? 1 : 0.6 }}
+              >💺</button>
+              {g.seat_element_id && (
+                <span style={{ fontSize: 11, opacity: 0.7 }} title="Sitzplatz zugewiesen">✓</span>
+              )}
+              <button onClick={() => void handleDelete(g.id)} aria-label={`Lösche ${g.name}`}>🗑</button>
+            </div>
+          </li>
+        ))}
+        {!loading && filtered.length === 0 && (
+          <li style={{ opacity: 0.5, padding: 8 }}>Keine Gäste gefunden.</li>
+        )}
+      </ul>
+    </div>
+  );
+};
+
+export default GuestPanel;

frontend/src/components/LayoutBar.tsx

@@ -0,0 +1,220 @@
+/**
+ * Task G2 – LayoutBar: Layout-Verwaltung + Viewport-Minimap-Widget.
+ *
+ * - Listet Layouts des aktiven Dokuments (documentService-Fallback)
+ * - Klick auf Eintrag = zoom-to gespeichertem Viewport (Bridge)
+ * - „+“ speichert aktuellen Viewport als neues Layout
+ * - „🗑“ löscht Layout; je Eintrag Minimap (Modellbereich + Viewport-Rechteck)
+ */
+import React, { useCallback, useEffect, useState } from 'react';
+import type { LayoutDefinition } from '../types/cad.types';
+import { getActiveDocument, onActiveDocumentChanged } from '../kernel/document/documentService';
+import { insertTitleBlockForLayout } from '../services/titleBlockService';
+import { printLayout } from '../services/printService';
+import { useT } from '../i18n/strings';
+
+export interface LayoutView {
+  center: { x: number; y: number };
+  scale: number;
+}
+
+export interface LayoutBridge {
+  zoomTo(center: { x: number; y: number }, scale: number): void;
+  getView(): LayoutView;
+}
+
+interface LayoutBarProps {
+  /** Aktives Dokument (Fallback: documentService, Task G2 UI-Unabhängigkeit). */
+  doc?: {
+    getAllLayouts(): LayoutDefinition[];
+    addLayout(l: LayoutDefinition): void;
+    deleteLayout(id: string): void;
+    getAllElements?(): Array<{ x: number; y: number; width: number; height: number }>;
+    onChanged?(cb: () => void): () => void;
+  } | null;
+  /** Canvas-Bridge (Fallback: window.__v2LayoutBridge aus CanvasArea). */
+  bridge?: LayoutBridge | null;
+}
+
+interface Rect { x: number; y: number; w: number; h: number }
+
+/**
+ * Minimap-Geometrie (Task G2, rein & getestet):
+ * Modell-BBox füllt das Widget (Stretch mit 6px Padding); ohne Elemente
+ * Volles Widget. Viewport-Rechteck = nominale Ansicht 800×600/scale Welt.
+ */
+export function computeMinimapRects(
+  elements: Array<{ x: number; y: number; width: number; height: number }>,
+  view: LayoutView,
+  widgetW: number,
+  widgetH: number,
+): { model: Rect; view: Rect } {
+  if (!Array.isArray(elements) || elements.length === 0) {
+    return { model: { x: 0, y: 0, w: widgetW, h: widgetH }, view: { x: 0, y: 0, w: widgetW, h: widgetH } };
+  }
+  let minX = Infinity, minY = Infinity, maxX = -Infinity, maxY = -Infinity;
+  for (const el of elements) {
+    minX = Math.min(minX, el.x - el.width / 2);
+    minY = Math.min(minY, el.y - el.height / 2);
+    maxX = Math.max(maxX, el.x + el.width / 2);
+    maxY = Math.max(maxY, el.y + el.height / 2);
+  }
+  if (!isFinite(minX) || maxX - minX <= 0 || maxY - minY <= 0) {
+    return { model: { x: 0, y: 0, w: widgetW, h: widgetH }, view: { x: 0, y: 0, w: widgetW, h: widgetH } };
+  }
+  const PAD = 6;
+  const model: Rect = { x: PAD, y: PAD, w: widgetW - 2 * PAD, h: widgetH - 2 * PAD };
+  const wx = (w: number) => model.x + ((w - minX) / (maxX - minX)) * model.w;
+  const wy = (w: number) => model.y + ((w - minY) / (maxY - minY)) * model.h;
+  const viewW = 800 / view.scale;
+  const viewH = 600 / view.scale;
+  const viewRect: Rect = {
+    x: wx(view.center.x - viewW / 2),
+    y: wy(view.center.y - viewH / 2),
+    w: (viewW / (maxX - minX)) * model.w,
+    h: (viewH / (maxY - minY)) * model.h,
+  };
+  return { model, view: viewRect };
+}
+
+const WIDGET_W = 100;
+const WIDGET_H = 80;
+
+const LayoutBar: React.FC<LayoutBarProps> = ({ doc: docProp, bridge: bridgeProp }) => {
+  const t = useT();
+
+  const [doc, setDoc] = useState(docProp ?? getActiveDocument());
+  const [layouts, setLayouts] = useState<LayoutDefinition[]>([]);
+
+  const bridge: LayoutBridge | null = bridgeProp ??
+    ((typeof window !== 'undefined' ? (window as unknown as { __v2LayoutBridge?: LayoutBridge }).__v2LayoutBridge : undefined) ?? null);
+
+  const reload = useCallback(() => {
+    setLayouts(doc ? doc.getAllLayouts() : []);
+  }, [doc]);
+
+  useEffect(() => {
+    reload();
+    // Live-Updates (auch Remote via CRDT), falls das Doc es anbietet
+    const off = doc?.onChanged?.(reload);
+    return () => { if (off) off(); };
+  }, [reload]);
+
+  // Fallback-Verdrahtung: aktives Dokument aus dem documentService
+  useEffect(() => {
+    if (docProp) return;
+    setDoc(getActiveDocument());
+    const off = onActiveDocumentChanged(() => setDoc(getActiveDocument()));
+    return off;
+  }, [docProp]);
+
+  const handleAdd = () => {
+    if (!bridge || !doc) return;
+    const view = bridge.getView();
+    doc.addLayout({
+      id: `layout-${Date.now()}`,
+      name: `Layout ${layouts.length + 1}`,
+      viewport: { center: { ...view.center }, scale: view.scale },
+    });
+    reload();
+  };
+
+  const handleDelete = (id: string) => {
+    doc?.deleteLayout(id);
+    reload();
+  };
+
+  const handlePrint = () => {
+    void printLayout();
+  };
+
+  const handleZoomTo = (l: LayoutDefinition) => {
+    bridge?.zoomTo(l.viewport.center, l.viewport.scale);
+  };
+
+  const elements = doc?.getAllElements?.() ?? [];
+
+  return (
+    <div className="layout-bar" data-testid="layout-bar">
+      <div className="layout-bar-header">
+        <span className="layout-bar-title">{t('layouts.title')}</span>
+        <button
+          type="button"
+          className="layout-bar-add"
+          title={t('layouts.add')}
+          onClick={handleAdd}
+          disabled={!bridge || !doc}
+        >+</button>
+        <button
+          type="button"
+          className="layout-bar-print screen-only"
+          title={t('layouts.print')}
+          onClick={handlePrint}
+        >🖨</button>
+      </div>
+      {layouts.length === 0 ? (
+        <div className="layout-bar-empty">{t('layouts.empty')}</div>
+      ) : (
+        <div className="layout-bar-list">
+          {layouts.map((l) => {
+            const rects = computeMinimapRects(elements, l.viewport, WIDGET_W, WIDGET_H);
+            return (
+              <div key={l.id} className="layout-bar-item">
+                <button
+                  type="button"
+                  className="layout-bar-entry"
+                  data-testid={`layout-entry-${l.id}`}
+                  title={t('layouts.zoomto', l.name)}
+                  onClick={() => handleZoomTo(l)}
+                >
+                  <svg
+                    data-testid={`layout-minimap-${l.id}`}
+                    width={WIDGET_W}
+                    height={WIDGET_H}
+                    viewBox={`0 0 ${WIDGET_W} ${WIDGET_H}`}
+                    className="layout-minimap"
+                  >
+                    <rect
+                      x={rects.model.x} y={rects.model.y}
+                      width={rects.model.w} height={rects.model.h}
+                      fill="rgba(255,255,255,0.05)" stroke="rgba(255,255,255,0.25)" strokeWidth="1"
+                    />
+                    <rect
+                      x={rects.view.x} y={rects.view.y}
+                      width={Math.max(2, rects.view.w)} height={Math.max(2, rects.view.h)}
+                      fill="rgba(74,144,217,0.25)" stroke="#4a90d9" strokeWidth="1"
+                    />
+                  </svg>
+                  <span className="layout-bar-name">{l.name}</span>
+                </button>
+                <button
+                  type="button"
+                  className="layout-bar-tb"
+                  title={t('layouts.titleblock', l.name)}
+                  onClick={() => {
+                    if (!doc) return;
+                    insertTitleBlockForLayout(doc as never, l.id, {
+                      project: l.name,
+                      date: new Date().toISOString().slice(0, 10),
+                      scale: `1:${Math.max(1, Math.round(1 / (l.viewport.scale || 1)))}`,
+                      author: 'WebCAD',
+                    });
+                    reload();
+                  }}
+                >🏷</button>
+                <button
+                  type="button"
+                  className="layout-bar-del"
+                  title={t('layouts.delete', l.name)}
+                  onClick={() => handleDelete(l.id)}
+                >🗑</button>
+              </div>
+            );
+          })}
+        </div>
+      )}
+    </div>
+  );
+};
+
+export default LayoutBar;

frontend/src/components/LibraryProviderPanel.tsx

@@ -0,0 +1,84 @@
+/**
+ * Task F4 – UI für LibraryProviderExtensions.
+ *
+ * Lädt alle übergebenen Provider (builtin/user/global) und rendert je Ordner
+ * eine Sektion mit Thumbnail-Blöcken. Jeder Block ist als DragSource an den
+ * bestehenden 'text/global-block-data'-Kanal angebunden (DragDrop → Canvas).
+ */
+import React, { useEffect, useState } from 'react';
+import type { LibraryProviderExtension, LibBlock } from '../plugins/types';
+
+interface Props {
+  providers: LibraryProviderExtension[];
+}
+
+interface Section { key: string; label: string; blocks: LibBlock[]; }
+
+const LibraryProviderPanel: React.FC<Props> = ({ providers }) => {
+  const [sections, setSections] = useState<Section[]>([]);
+
+  useEffect(() => {
+    let cancelled = false;
+    (async () => {
+      const out: Section[] = [];
+      for (const provider of providers) {
+        try {
+          const folders = await provider.listFolders();
+          for (const folder of folders) {
+            try {
+              const blocks = await provider.listBlocks(folder.id);
+              if (blocks.length > 0) {
+                out.push({ key: `${provider.id}/${folder.id}`, label: folder.label, blocks });
+              }
+            } catch {
+              // Ordner bei Fehler überspringen
+            }
+          }
+        } catch {
+          // Provider bei Fehler überspringen
+        }
+      }
+      if (!cancelled) setSections(out);
+    })();
+    return () => {
+      cancelled = true;
+    };
+  }, [providers]);
+
+  const handleDragStart = (e: React.DragEvent, block: LibBlock) => {
+    const payload = typeof block.payload === 'string' ? block.payload : JSON.stringify(block.payload ?? []);
+    e.dataTransfer.setData('text/global-block-data', payload);
+    e.dataTransfer.effectAllowed = 'copy';
+  };
+
+  if (sections.length === 0) return null;
+
+  return (
+    <div className="lib-provider-panel">
+      {sections.map((section) => (
+        <div className="lprov-section" key={section.key}>
+          <div className="lprov-title">{section.label}</div>
+          <div className="lprov-grid">
+            {section.blocks.map((block) => (
+              <button
+                key={block.id}
+                type="button"
+                className="lprov-block"
+                aria-label={block.name}
+                title={block.name}
+                draggable
+                onDragStart={(e) => handleDragStart(e, block)}
+              >
+                {block.thumbnail
+                  ? <span className="tree-thumb" dangerouslySetInnerHTML={{ __html: block.thumbnail }} />
+                  : <span className="lib-grid-placeholder">📦</span>}
+              </button>
+            ))}
+          </div>
+        </div>
+      ))}
+    </div>
+  );
+};
+
+export default LibraryProviderPanel;

frontend/src/components/PropertiesPanel.tsx

@@ -1,6 +1,9 @@
 import React, { useState, useEffect } from 'react';
+import { polygonArea } from '../tools/modification/geometry';
+import { formatArea } from '../utils/format';
 import type { PropertiesPanelProps } from '../types/ui.types';
 import { formatInputValue, parseDistance, type UnitType } from '../utils/format';
+import { getActiveDocument } from '../kernel/document/documentService';
 
 const parseNum = (s: string) => parseFloat(s.replace(/[^0-9.\-]/g, '')) || 0;
 
@@ -69,7 +72,43 @@ const PropertiesPanel: React.FC<PropertiesPanelProps> = ({
     <>
       <div className="panel-section">
         <div className="panel-section-title">
-          <span>Auswahl {el ? `· ${el.type}` : ''}</span>
+          <span>Auswahl {el ? `· ${el.type}
+        {((el.type === 'polygon' || el.type === 'polyline') && ((el.properties.points as Array<{ x: number; y: number }> | undefined)?.length ?? 0) >= 3) && (
+          <div className="prop-row">
+            <label className="prop-label">Fläche</label>
+            <span className="prop-value">{formatArea(polygonArea(el.properties.points as Array<{ x: number; y: number }>), unit, scaleFactor)}</span>
+          </div>
+        )}
+
+        {/* ─── Task D12: Block-Attribute-Formular (block_instance) ─── */}
+        {el.type === 'block_instance' && (() => {
+          const blockId = el.properties.blockId as string | undefined;
+          if (!blockId) return null;
+          const block = getActiveDocument()?.getBlock(blockId);
+          const attrDefs = block?.attrDefs ?? [];
+          if (attrDefs.length === 0) return null;
+          const attrValues = (el.properties.attrValues as Record<string, string> | undefined) ?? {};
+          return (
+            <div className="panel-section">
+              <div className="panel-section-title">Block-Attribute</div>
+              {attrDefs.map((def) => (
+                <div className="prop-row" key={def.tag}>
+                  <label className="prop-label" title={def.prompt}>{def.tag}</label>
+                  <input
+                    className="prop-input"
+                    type="text"
+                    value={attrValues[def.tag] ?? def.defaultValue ?? ''}
+                    placeholder={def.prompt}
+                    onChange={(ev) => {
+                      const next = { ...attrValues, [def.tag]: ev.target.value };
+                      onUpdateProperty('attrValues', next);
+                    }}
+                  />
+                </div>
+              ))}
+            </div>
+          );
+        })()}` : ''}</span>
           <div style={{ display: 'flex', gap: '4px' }}>
             {onDelete && el && (
               <button

frontend/src/components/RibbonBar.tsx

@@ -1,5 +1,8 @@
 import React from 'react';
+import { getUIMode, useUIMode } from '../services/uiModeService';
 import type { RibbonBarProps, RibbonTab } from '../types/ui.types';
+import { pluginRegistry } from '../plugins';
+import { V2_TOOLS_ENABLED } from '../kernel/featureFlags';
 
 const tabs: Array<{ id: RibbonTab; label: string; svg: React.ReactNode }> = [
   { id: 'start', label: 'Start', svg: <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round"><path d="m3 9 9-7 9 7v11a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2z"/><polyline points="9 22 9 12 15 12 15 22"/></svg> },
@@ -15,7 +18,10 @@ const RibbonBar: React.FC<RibbonBarProps> = ({
   activeTab, onTabChange, onAction,
   canvasBgColor = '#1e1e2e', gridColor = '#3a3a4a', rulerEnabled = true,
   onCanvasBgColorChange, onGridColorChange, onToggleRuler,
+  onIsV2ToolActive,
 }) => {
+  const uiMode = useUIMode();
+
   return (
     <nav className="ribbon" role="navigation" aria-label="Hauptwerkzeuge">
       <div className="ribbon-tabs" role="tablist">
@@ -36,6 +42,40 @@ const RibbonBar: React.FC<RibbonBarProps> = ({
       </div>
 
       <div className="ribbon-content" id="ribbon-content">
+        {/* ===== V2 TOOLS (Task A4.13/A4.14: Standard aktiv — Opt-out via VITE_TOOL_DISPATCHER=legacy) ===== */}
+        {activeTab === 'canvas' && V2_TOOLS_ENABLED && (
+          <div style={{
+            display: 'flex', flexWrap: 'wrap', gap: '6px', alignItems: 'center',
+            padding: '8px 4px', width: '100%',
+            borderBottom: '1px solid var(--color-border, #333)', marginBottom: '8px',
+          }}>
+            <span style={{ fontSize: '11px', color: 'var(--color-ki, #8a8aff)', marginRight: '4px' }}>V2:</span>
+            {pluginRegistry.getToolsV2()
+              .filter((tool) => uiMode === 'pro' || (tool.manifest.tags ?? []).includes('basic'))
+              .map((tool) => {
+              const isActive = onIsV2ToolActive?.(tool.manifest.id);
+              return (
+                <button
+                  key={tool.manifest.id}
+                  data-v2tool={tool.manifest.id}
+                  title={tool.manifest.description ?? tool.manifest.label}
+                  onClick={() => onAction(`v2tool:${tool.manifest.id}`)}
+                  style={{
+                    display: 'flex', alignItems: 'center', gap: '4px',
+                    padding: '5px 9px', borderRadius: '4px', fontSize: '12px',
+                    cursor: 'pointer', border: '1px solid var(--color-border, #333)',
+                    background: isActive ? 'rgba(80,250,123,0.15)' : 'var(--color-bg-secondary, #2a2a3a)',
+                    color: isActive ? '#50fa7b' : 'inherit',
+                    fontWeight: isActive ? 600 : 400,
+                  }}
+                >
+                  <span style={{ fontFamily: 'monospace' }}>{tool.manifest.icon}</span>
+                  <span>{tool.manifest.label}</span>
+                </button>
+              );
+            })}
+          </div>
+        )}
         {/* ===== START TAB ===== */}
         {activeTab === 'start' && (
           <>
@@ -289,6 +329,10 @@ const RibbonBar: React.FC<RibbonBarProps> = ({
                   <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round"><path d="M3 3v5h5"/><path d="M3.05 13A9 9 0 1 0 6 5.3L3 8"/><path d="M12 7v5l4 2"/></svg>
                   <span>Historie</span>
                 </button>
+                <button className="ribbon-btn" title="Gäste-Verwaltung" onClick={() => onAction('guests')}>
+                  <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round"><path d="M17 21v-2a4 4 0 0 0-4-4H5a4 4 0 0 0-4 4v2"/><circle cx="9" cy="7" r="4"/><path d="M23 21v-2a4 4 0 0 0-3-3.87"/><path d="M16 3.13a4 4 0 0 1 0 7.75"/></svg>
+                  <span>Gäste</span>
+                </button>
               </div>
               <div className="ribbon-group-label">Extras</div>
             </div>

frontend/src/components/RightSidebar.tsx

@@ -1,9 +1,14 @@
 import React, { useCallback } from 'react';
 import type { RightSidebarProps, RightPanel } from '../types/ui.types';
+import type { LibraryProviderExtension } from '../plugins/types';
 import PropertiesPanel from './PropertiesPanel';
 import LayerPanel from './LayerPanel';
 import BlockLibrary from './BlockLibrary';
 import BlockLibraryTree from './BlockLibraryTree';
+import LibraryProviderPanel from './LibraryProviderPanel';
+import { pluginRegistry, builtinCatalogProvider } from '../plugins';
+import { makeUserLibraryProvider, makeGlobalLibraryProvider } from '../plugins/builtin/library/providers';
+import { useMemo } from 'react';
 import KICopilot from './KICopilot';
 
 const MIN_RIGHTBAR_WIDTH = 200;
@@ -39,6 +44,23 @@ const RightSidebar: React.FC<RightSidebarProps> = ({
   rightbarWidth = 300,
   onWidthChange,
 }) => {
+  const libraryProviders = useMemo(() => {
+    const list: LibraryProviderExtension[] = [];
+    const seen = new Set<string>();
+    const push = (p: LibraryProviderExtension) => {
+      if (p && !seen.has(p.id)) {
+        seen.add(p.id);
+        list.push(p);
+      }
+    };
+    for (const p of pluginRegistry.getLibraryProviders()) push(p);
+    push(builtinCatalogProvider);
+    if (blocks) push(makeUserLibraryProvider(blocks));
+    if (token) push(makeGlobalLibraryProvider(token));
+    return list;
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [blocks, token]);
+
   const handleResizeMouseDown = useCallback((e: React.MouseEvent) => {
     e.preventDefault();
     e.stopPropagation();
@@ -138,6 +160,7 @@ const RightSidebar: React.FC<RightSidebarProps> = ({
                       }}
                     />
                   )}
+                  <LibraryProviderPanel providers={libraryProviders} />
                 </>
               )}
             </div>

frontend/src/components/Topbar.tsx

@@ -1,12 +1,18 @@
 import React from 'react';
 import type { TopbarProps } from '../types/ui.types';
 import type { UnitType } from '../utils/format';
+import { useUIMode, toggleUIMode, getUIMode } from '../services/uiModeService';
+import { useT } from '../i18n/strings';
 
 const Topbar: React.FC<TopbarProps> = ({
   projectName, savedStatus, onUndo, onRedo, onThemeToggle, theme,
   onOpenSettings, onOpenLeftDrawer, onOpenRightDrawer,
   unit = 'mm', onUnitChange, onNavigateBack,
 }) => {
+  const t = useT();
+
+  const uiMode = useUIMode();
+
   return (
     <header className="topbar" role="banner">
       <div className="topbar-left">
@@ -33,6 +39,14 @@ const Topbar: React.FC<TopbarProps> = ({
         <span className="saved-badge" aria-label="Status: Alle Änderungen gespeichert">{savedStatus}</span>
       </div>
       <div className="topbar-right">
+        <button
+          className="icon-btn-top"
+          title={uiMode === 'pro' ? t('mode.toSimple') : t('mode.toPro')}
+          aria-label={uiMode === 'pro' ? t('mode.toSimple') : t('mode.toPro')}
+          onClick={toggleUIMode}
+        >
+          {uiMode === 'pro' ? '😊' : '🛠'}
+        </button>
         <button className="icon-btn-top" aria-label="Rückgängig (Strg+Z)" title="Rückgängig (Strg+Z)" onClick={onUndo}>
           <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round"><path d="M3 7v6h6"/><path d="M21 17a9 9 0 0 0-15-6.7L3 13"/></svg>
         </button>

frontend/src/components/V2HistoryPanel.tsx

@@ -0,0 +1,164 @@
+/**
+ * V2HistoryPanel – History-Anzeige für das V2-Dokument (Task A4.12).
+ *
+ * Liest die Undo/Redo-Stacks des aktiven Dokuments (documentService).
+ * Klick auf einen aktiven Eintrag: macht alles DANACH rückgängig.
+ * Redo-Einträge sind rein informativ (gezielter Sprung nicht nativ).
+ *
+ * Wird statt des Legacy HistoryPanel gerendert, wenn
+ * VITE_TOOL_DISPATCHER=v2 gesetzt ist (App.tsx entscheidet).
+ */
+import React, { useEffect, useState } from 'react';
+import { getActiveDocument, undoActive, redoActive } from '../kernel/document/documentService';
+import type { CADDocument } from '../kernel/document/CADDocument';
+
+type StackKind = 'undo' | 'redo';
+interface StackItemInfo {
+  kind: StackKind;
+  index: number;   // Position im jeweiligen Stack (0 = ältester)
+}
+
+const V2HistoryPanel: React.FC<{ onClose: () => void }> = ({ onClose }) => {
+  const [doc, setDoc] = useState<CADDocument | null>(getActiveDocument());
+  const [, bump] = useState(0);
+
+  // Auf Dokumentwechsel reagieren + bei Doc-Änderung neu rendern
+  useEffect(() => {
+    const unsubChange = doc?.onChanged(() => bump((b) => b + 1));
+    const interval = setInterval(() => {
+      const active = getActiveDocument();
+      if (active !== doc) setDoc(active);
+    }, 500); // einfacher Registry-Poll bis A5 einen Hook liefert
+    return () => {
+      unsubChange?.();
+      clearInterval(interval);
+    };
+  }, [doc]);
+
+  const um = doc?.getUndoManager();
+  const undoCount = um ? um.undoStack.length : 0;
+  const redoCount = um ? um.redoStack.length : 0;
+  const items: Array<StackItemInfo & { isCurrent: boolean }> = [];
+  // Neueste zuerst auflisten:
+  for (let i = undoCount - 1; i >= 0; i--) {
+    items.push({ kind: 'undo', index: i, isCurrent: i === undoCount - 1 });
+  }
+  for (let i = redoCount - 1; i >= 0; i--) {
+    items.push({ kind: 'redo', index: i, isCurrent: false });
+  }
+
+  /** Macht alle Schritte nach slotIndex rückgängig (slot 0 = ältester). */
+  const undoUntilSlot = (slotIndex: number): void => {
+    if (!doc) return;
+    const targetLen = slotIndex + 1;
+    let guard = 0;
+    while (
+      doc.canUndo() &&
+      doc.getUndoManager().undoStack.length > targetLen &&
+      guard < 500
+    ) {
+      doc.undo();
+      guard++;
+    }
+  };
+
+  const shellStyle: React.CSSProperties = {
+    position: 'fixed', top: '50%', right: '320px', transform: 'translateY(-50%)',
+    background: 'var(--color-bg-primary, #1e1e2e)', borderRadius: '8px',
+    padding: '16px', width: '280px', maxHeight: '60vh', overflow: 'auto',
+    border: '1px solid var(--color-border, #333)', zIndex: 900,
+    color: 'var(--color-text, #e0e0e0)',
+  };
+
+  if (!doc || items.length === 0) {
+    return (
+      <div style={shellStyle}>
+        <Header onClose={onClose} count={items.length} />
+        <p style={{ fontSize: '13px', color: '#888' }}>
+          {doc ? 'Keine Historie vorhanden.' : 'Kein V2-Dokument aktiv (Flag aus?).'}
+        </p>
+        <UndoRedoButtons doc={doc} />
+      </div>
+    );
+  }
+
+  return (
+    <div style={shellStyle}>
+      <Header onClose={onClose} count={items.length} />
+      <UndoRedoButtons doc={doc} />
+      <div style={{ display: 'flex', flexDirection: 'column', gap: '2px' }}>
+        {items.map((item) => (
+          <button
+            key={`${item.kind}-${item.index}`}
+            onClick={() => item.kind === 'undo' && undoUntilSlot(item.index)}
+            title={item.kind === 'undo'
+              ? 'Klicken: alles danach rückgängig machen'
+              : 'Redo-Eintrag (nur anzeigbar)'}
+            style={{
+              display: 'flex', alignItems: 'center', gap: '8px',
+              padding: '6px 8px', borderRadius: '4px',
+              cursor: item.kind === 'undo' ? 'pointer' : 'default',
+              border: item.isCurrent && item.kind === 'undo'
+                ? '1px solid rgba(80,250,123,0.4)' : 'none',
+              textAlign: 'left', width: '100%',
+              background: item.isCurrent && item.kind === 'undo'
+                ? 'rgba(80, 250, 123, 0.12)' : item.kind === 'redo'
+                ? 'rgba(255,255,255,0.03)' : 'transparent',
+              color: item.kind === 'redo' ? '#888' : 'var(--color-text, #e0e0e0)',
+              fontWeight: item.isCurrent && item.kind === 'undo' ? 600 : 400,
+              fontSize: '13px', opacity: item.kind === 'redo' ? 0.6 : 1,
+            }}
+          >
+            <span style={{ fontSize: '10px', minWidth: '44px', color: '#666' }}>
+              {item.kind === 'undo' ? `Schritt ${item.index + 1}` : 'Redo'}
+            </span>
+            {item.isCurrent && item.kind === 'undo' && (
+              <span style={{ fontSize: '10px', color: '#50fa7b' }}>● aktuell</span>
+            )}
+          </button>
+        ))
+      }
+      </div>
+    </div>
+  );
+};
+
+function Header({ onClose, count }: { onClose: () => void; count: number }): JSX.Element {
+  return (
+    <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', marginBottom: '12px' }}>
+      <h3 style={{ margin: 0, fontSize: '15px' }}>Historie V2{count > 0 ? ` (${count})` : ''}</h3>
+      <button onClick={onClose} style={{ background: 'none', border: 'none', color: 'inherit', cursor: 'pointer', fontSize: '18px' }}>×</button>
+    </div>
+  );
+}
+
+function UndoRedoButtons({ doc }: { doc: CADDocument | null }): JSX.Element {
+  return (
+    <div style={{ display: 'flex', gap: '8px', marginBottom: doc && (doc.canUndo() || doc.canRedo()) ? '10px' : '4px' }}>
+      <button
+        onClick={() => undoActive()}
+        disabled={!doc?.canUndo()}
+        title="Strg+Z"
+        style={btnStyle(doc?.canUndo() ?? false)}
+      >↶ Undo</button>
+      <button
+        onClick={() => redoActive()}
+        disabled={!doc?.canRedo()}
+        title="Strg+Y"
+        style={btnStyle(doc?.canRedo() ?? false)}
+      >↷ Redo</button>
+    </div>
+  );
+}
+
+function btnStyle(enabled: boolean): React.CSSProperties {
+  return {
+    padding: '5px 12px', borderRadius: '4px', fontSize: '12px',
+    cursor: enabled ? 'pointer' : 'not-allowed',
+    border: '1px solid var(--color-border, #333)',
+    background: 'var(--color-bg-secondary, #2a2a3a)',
+    color: enabled ? 'inherit' : '#555',
+  };
+}
+
+export default V2HistoryPanel;

frontend/src/crdt/YjsDocument.ts

@@ -6,6 +6,7 @@ import * as Y from 'yjs';
 import type { CADElement, CADLayer, BlockDefinition } from '../types/cad.types';
 import type { ElementGroup } from '../tools/modification/GroupTool';
 import type { BackgroundConfig } from '../services/backgroundService';
+import type { LayoutDefinition } from '../types/cad.types';
 
 export interface YjsDocumentData {
   elements: Y.Map<CADElement>;
@@ -14,6 +15,7 @@ export interface YjsDocumentData {
   meta: Y.Map<unknown>;
   groups: Y.Map<ElementGroup>;
   bgConfig: Y.Map<BackgroundConfig>;
+  layouts: Y.Map<LayoutDefinition>; // Task G1
 }
 
 export class YjsDocument {
@@ -29,6 +31,7 @@ export class YjsDocument {
       meta: this.doc.getMap<unknown>('meta'),
       groups: this.doc.getMap<ElementGroup>('groups'),
       bgConfig: this.doc.getMap<BackgroundConfig>('bgConfig'),
+      layouts: this.doc.getMap<LayoutDefinition>('layouts'),
     };
   }
 
@@ -57,6 +60,11 @@ export class YjsDocument {
     return Array.from(this.data.bgConfig.values());
   }
 
+  /** Get all layouts as a plain array (Task G1) */
+  getLayouts(): LayoutDefinition[] {
+    return Array.from(this.data.layouts.values());
+  }
+
   /** Add or update a single element */
   setElement(el: CADElement): void {
     this.doc.transact(() => {

frontend/src/i18n/strings.ts

@@ -0,0 +1,105 @@
+/**
+ * Task H4 – i18n-Grundlage: zentrale Strings-Maps de/en.
+ *
+ * t(key) liefert den Text der aktuellen Sprache; unbekannte Keys
+ * fallen auf den Key zurück (im Code sichtbar, lint-bar über Tests).
+ * Sprache persistiert in localStorage ('webcad.language', Default de).
+ * Komponenten nutzen useT() für Live-Updates bei Sprachwechsel.
+ *
+ * Vollständige mechanische Ersetzung ALLER Komponenten-Texte ist
+ * teilautomatisierbares Follow-up; hier liegt die Infrastruktur und
+ * die Kern-UI-Texte (LayoutBar, Modus).
+ */
+import { useEffect, useState } from 'react';
+
+export const LANGUAGES = ['de', 'en'] as const;
+export type Language = (typeof LANGUAGES)[number];
+
+type StringEntry = string | ((arg?: string) => string);
+
+const STORAGE_KEY = 'webcad.language';
+
+/** Zentrale Text-Maps (Key-Pfad → Text oder parametrisierte Funktion). */
+const DE: Record<string, StringEntry> = {
+  'layouts.title': 'Layouts',
+  'layouts.add': 'Layout hinzufügen',
+  'layouts.empty': 'Keine Layouts',
+  'layouts.delete': (n?: string) => 'Layout ' + (n ?? '') + ' löschen',
+  'layouts.print': 'Layout drucken (A4 landscape)',
+  'layouts.titleblock': (n?: string) => 'Titelblock für ' + (n ?? '') + ' einfügen/aktualisieren',
+  'layouts.zoomto': (n?: string) => 'Zoom zu ' + (n ?? ''),
+  'mode.toSimple': 'Zum einfachen Modus wechseln',
+  'mode.toPro': 'Zum Profi-Modus wechseln',
+};
+
+const EN: Record<string, StringEntry> = {
+  'layouts.title': 'Layouts',
+  'layouts.add': 'Add layout',
+  'layouts.empty': 'No layouts',
+  'layouts.delete': (n?: string) => 'Delete layout ' + (n ?? ''),
+  'layouts.print': 'Print layout (A4 landscape)',
+  'layouts.titleblock': (n?: string) => 'Insert/update title block for ' + (n ?? ''),
+  'layouts.zoomto': (n?: string) => 'Zoom to ' + (n ?? ''),
+  'mode.toSimple': 'Switch to simple mode',
+  'mode.toPro': 'Switch to pro mode',
+};
+
+function mapFor(lang: Language): Record<string, StringEntry> {
+  return lang === 'en' ? EN : DE;
+}
+
+function readStored(): Language {
+  try {
+    const raw = localStorage.getItem(STORAGE_KEY);
+    if (raw === 'de' || raw === 'en') return raw;
+  } catch {
+    // localStorage nicht verfügbar
+  }
+  return 'de';
+}
+
+let current: Language = readStored();
+const listeners = new Set<(lang: Language) => void>();
+
+/** Aktuelle Sprache. */
+export function getLanguage(): Language {
+  return current;
+}
+
+/** Sprache wechseln und persistieren. */
+export function setLanguage(lang: Language): void {
+  current = lang;
+  try {
+    localStorage.setItem(STORAGE_KEY, lang);
+  } catch {
+    // Persistenz optional
+  }
+  for (const cb of listeners) cb(lang);
+}
+
+/** Subscribe auf Sprachwechsel; gibt Unsubscribe zurück. */
+export function subscribeLanguage(cb: (lang: Language) => void): () => void {
+  listeners.add(cb);
+  return () => { listeners.delete(cb); };
+}
+
+/**
+ * Übersetzung: t('key') bzw. t('key', arg) für parametrisierte Texte.
+ * Unbekannter Key → Key als Fallback (offensichtlich sichtbar).
+ */
+export function t(key: string, arg?: string): string {
+  const entry = mapFor(current)[key];
+  if (typeof entry === 'function') return entry(arg);
+  if (typeof entry === 'string') return entry;
+  return key;
+}
+
+/** React-Hook: erzwingt Re-Render bei Sprachwechsel. */
+export function useT(): typeof t {
+  const [, force] = useState(0);
+  useEffect(() => {
+    const off = subscribeLanguage(() => force((n) => n + 1));
+    return off;
+  }, []);
+  return t;
+}

frontend/src/interaction/dispatcher.ts

@@ -0,0 +1,157 @@
+/**
+ * dispatcher.ts – InteractionDispatcher (Task A2).
+ *
+ * Ersetzt langfristig den 1157-Zeilen-Switch der InteractionEngine:
+ * - Routet DOM-Pointer-/Key-Events an das AKTIVE V2-Werkzeug (ToolExtensionV2)
+ * - Normalisiert Events (pointer.ts) zu Weltkoordinaten
+ * - Führt eine ToolSession als Down/Up-Guard
+ * - Kein Werkzeugwissen! Alle Logik liegt in den Plugins.
+ *
+ * Aktivierung per Feature-Flag VITE_TOOL_DISPATCHER=v2 (CanvasArea, A2 Schritt 4).
+ */
+import type { ToolExtensionV2, ToolContext } from '../plugins/types';
+import { pluginRegistry } from '../plugins/PluginRegistry';
+import { toToolPointerEvent } from './pointer';
+import { ToolSession } from './session';
+import type { ZoomPanController } from '../canvas/ZoomPanController';
+
+export interface DispatcherDeps {
+  zoomPan: ZoomPanController;
+  /** Liefert Optionsstände je ToolId (typisch: toolStore.optionValues). */
+  getOptions?(toolId: string): Record<string, unknown>;
+  /** Statuszeile (typisch: StatusBar-Bridge). */
+  setStatus?(msg: string): void;
+  /** Live-Vorschau-Ziel (typisch RenderEngine.setPreviewElement). */
+  setPreview?(el: unknown | null): void;
+  /** Tool-Nachschlag überschreibbar (Default: aktive Registry-Tools). */
+  toolLookup?(toolId: string): ToolExtensionV2 | undefined;
+  /** Dokument-Fassade für Tools (ab A3; lazy pro Event abgefragt). */
+  getDoc?(): import('../kernel/document/CADDocument').CADDocument | undefined;
+  /** Selektions-Bridge für Tools (ab A3; lazy pro Event abgefragt). */
+  getSelectionBridge?(): import('../plugins/types').ToolSelectionBridge;
+}
+
+export class InteractionDispatcher {
+  private readonly canvas: HTMLCanvasElement;
+  private readonly deps: DispatcherDeps;
+  private readonly session = new ToolSession();
+  private active: ToolExtensionV2 | null = null;
+  private bound = false;
+
+  /** Zuletzt gesetzter Status-Text (für Tests/Debug). */
+  lastStatus = '';
+
+  constructor(canvas: HTMLCanvasElement, deps: DispatcherDeps) {
+    this.canvas = canvas;
+    this.deps = deps;
+    this.attach();
+  }
+
+  /** Setzt das aktive Werkzeug (null = deaktiviert Routing). */
+  setActive(toolId: string | null): void {
+    if (this.active && this.session.isActive) {
+      // Sitzung sauber abbrechen, bevor gewechselt wird
+      this.active.handlers.cancel?.(this.buildContext());
+      this.session.end();
+    }
+    if (!toolId) {
+      this.active = null;
+      return;
+    }
+    const lookup = this.deps.toolLookup ?? ((id: string) => pluginRegistry.getToolV2(id));
+    const tool = lookup(toolId);
+    if (!tool) {
+      console.warn(`[InteractionDispatcher] kein aktives V2-Tool '${toolId}'`);
+      this.active = null;
+      return;
+    }
+    this.active = tool;
+    this.setStatus(`${tool.manifest.label} aktiv`);
+  }
+
+  /** Aktives Werkzeug (oder null). */
+  getActive(): ToolExtensionV2 | null {
+    return this.active;
+  }
+
+  /** Entfernt alle Event-Listener (aufräumen beim Unmount). */
+  destroy(): void {
+    if (!this.bound) return;
+    this.canvas.removeEventListener('pointerdown', this.onDown);
+    window.removeEventListener('pointermove', this.onMove);
+    window.removeEventListener('pointerup', this.onUp);
+    window.removeEventListener('keydown', this.onKey);
+    this.bound = false;
+  }
+
+  // ── intern ───────────────────────────────────────────────
+
+  private attach(): void {
+    if (this.bound) return;
+    this.canvas.addEventListener('pointerdown', this.onDown);
+    window.addEventListener('pointermove', this.onMove);
+    window.addEventListener('pointerup', this.onUp);
+    window.addEventListener('keydown', this.onKey);
+    this.bound = true;
+  }
+
+  private buildContext(): import('../plugins/types').FullToolContext {
+    const toolId = this.active?.manifest.id ?? '';
+    return {
+      options: this.deps.getOptions?.(toolId) ?? {},
+      setStatus: (msg) => this.setStatus(msg),
+      setPreview: (el) => this.deps.setPreview?.(el),
+      doc: this.deps.getDoc?.(),
+      selection: this.deps.getSelectionBridge?.(),
+    };
+  }
+
+  private setStatus(msg: string): void {
+    this.lastStatus = msg;
+    this.deps.setStatus?.(msg);
+  }
+
+  private onDown = (e: PointerEvent): void => {
+    if (!this.active) return;
+    // Rechtsklick = Abbruch wie ESC
+    if (e.button === 2) {
+      this.cancelActive();
+      return;
+    }
+    const tpe = toToolPointerEvent(e, this.canvas, this.deps.zoomPan);
+    this.session.begin();
+    this.active.handlers.down?.(tpe, this.buildContext());
+  };
+
+  private onMove = (e: PointerEvent): void => {
+    if (!this.active || !this.session.isActive) return;
+    const tpe = toToolPointerEvent(e, this.canvas, this.deps.zoomPan);
+    this.active.handlers.move?.(tpe, this.buildContext());
+  };
+
+  private onUp = (e: PointerEvent): void => {
+    if (!this.active || !this.session.isActive) return;
+    const tpe = toToolPointerEvent(e, this.canvas, this.deps.zoomPan);
+    try {
+      this.active.handlers.up?.(tpe, this.buildContext());
+    } finally {
+      this.session.end();
+    }
+  };
+
+  private onKey = (e: KeyboardEvent): void => {
+    if (!this.active) return;
+    if (e.key === 'Escape') {
+      this.cancelActive();
+      return;
+    }
+    const consumed = this.active.handlers.key?.(e, this.buildContext()) === true;
+    if (consumed) e.preventDefault();
+  };
+
+  private cancelActive(): void {
+    if (!this.active) return;
+    this.active.handlers.cancel?.(this.buildContext());
+    this.session.end();
+  }
+}

frontend/src/interaction/index.ts

@@ -761,7 +761,23 @@ export class InteractionEngine {
       if (this.modifySelected.length === 1) {
         const first = this.state.points[0];
         const dist = distance(first, pt);
-        const offsetted = offsetElement(this.modifySelected[0], dist);
+        const base = this.modifySelected[0];
+        // Seitigkeit bestimmen: Kreuzprodukt der Linienrichtung mit Klickvektor.
+        // cross > 0 → Klick links der Laufrichtung (p1→p2) → side=+1, sonst -1.
+        let side: 1 | -1 = 1;
+        if (base.type === 'line' && base.properties.x1 !== undefined && base.properties.y1 !== undefined) {
+          const p1x = base.properties.x1 as number;
+          const p1y = base.properties.y1 as number;
+          const p2x = base.properties.x2 as number;
+          const p2y = base.properties.y2 as number;
+          const cross = (p2x - p1x) * (pt.y - p1y) - (p2y - p1y) * (pt.x - p1x);
+          side = cross >= 0 ? 1 : -1;
+        } else if ((base.type === 'circle' || base.type === 'arc') && base.properties.radius !== undefined) {
+          // Kreis/Bogen: Klick außerhalb → vergrößern (+1), innerhalb → verkleinern (-1)
+          const clickDist = Math.hypot(pt.x - base.x, pt.y - base.y);
+          side = clickDist >= base.properties.radius ? 1 : -1;
+        }
+        const offsetted = offsetElement(base, dist, side);
         // Create as new element (copy)
         this.onElementCreated?.({ ...offsetted, id: this.generateId() });
         this.resetModify();

frontend/src/interaction/pointer.ts

@@ -0,0 +1,53 @@
+/**
+ * pointer.ts – DOM-PointerEvent → ToolPointerEvent Normalisierung (Task A2).
+ * Konvertiert Bildschirmkoordinaten in Weltkoordinaten über ZoomPanController.
+ */
+import type { ToolPointerEvent } from '../plugins/types';
+import type { ZoomPanController } from '../canvas/ZoomPanController';
+
+/**
+ * Normalisiert ein Pointer/Mouse-Event zu einem ToolPointerEvent.
+ * @param e DOM-Event (MouseEvent ist Obermenge von PointerEvent-Feldern)
+ * @param canvas Das Canvas-Element (für offset-Koordinaten)
+ * @param zoomPan aktiver Zoom/Pan-Controller
+ */
+export function toToolPointerEvent(
+  e: MouseEvent,
+  canvas: HTMLCanvasElement,
+  zoomPan: ZoomPanController,
+): ToolPointerEvent {
+  const rect = canvas.getBoundingClientRect();
+  const sx = e.clientX - rect.left;
+  const sy = e.clientY - rect.top;
+  const world = zoomPan.screenToWorld(sx, sy);
+  return {
+    world: { x: world.x, y: world.y },
+    screen: { x: sx, y: sy },
+    button: e.button,
+    shift: e.shiftKey,
+    alt: e.altKey,
+    ctrl: e.ctrlKey || e.metaKey,
+  };
+}
+
+/** Fangt weitere Pointer-Events auf dem Canvas bis zum release (Pen/Tablet- Komfort). */
+export function capturePointer(canvas: HTMLCanvasElement, e: PointerEvent): void {
+  if (typeof canvas.setPointerCapture === 'function') {
+    try {
+      canvas.setPointerCapture(e.pointerId);
+    } catch {
+      /* pointerId evtl. schon ungültig — unkritisch */
+    }
+  }
+}
+
+/** Gibt einen vorherigen Pointer-Capture frei. */
+export function releasePointer(canvas: HTMLCanvasElement, e: PointerEvent): void {
+  if (typeof canvas.releasePointerCapture === 'function') {
+    try {
+      canvas.releasePointerCapture(e.pointerId);
+    } catch {
+      /* ignorieren */
+    }
+  }
+}

frontend/src/interaction/session.ts

@@ -0,0 +1,34 @@
+/**
+ * session.ts – Minimaler Werkzeug-Sitzungszustand (Task A2).
+ *
+ * phase 'idle'   : kein Ziehen aktiv, Tool wartet auf down
+ * phase 'active' : down ist erfolgt; Tool zieht/zeichnet bis up/cancel
+ *
+ * Der Dispatcher nutzt das, um move-Events nur während aktiver Sitzung an
+ * Handler durchzureichen (und als Guard gegen verlorene up-Events).
+ */
+export type ToolPhase = 'idle' | 'active';
+
+export class ToolSession {
+  private current: ToolPhase = 'idle';
+
+  /** Ist eine Zeichensitzung aktiv (zwischen down und up)? */
+  get isActive(): boolean {
+    return this.current === 'active';
+  }
+
+  /** Aktuelle Phase. */
+  get phase(): ToolPhase {
+    return this.current;
+  }
+
+  /** Startet eine Sitzung (nach einem gültigen down). */
+  begin(): void {
+    this.current = 'active';
+  }
+
+  /** Beendet die Sitzung regulär (up) oder abgebrochen (cancel/ESC). */
+  end(): void {
+    this.current = 'idle';
+  }
+}

frontend/src/kernel/document/CADDocument.ts

@@ -0,0 +1,217 @@
+/**
+ * CADDocument – Fassade über YjsDocument (Task A2b).
+ *
+ * - Elementar-CRUD auf CADElement/CADLayer
+ * - `transact(fn)`: Bündelt Änderungen zu EINEM Undo-Schritt
+ *   (kollaborativ korrekt via Y.UndoManager)
+ * - `undo()/redo()` wrappen den Manager; HistoryPanel liest später daraus (A4)
+ * - Keine Tool-Logik! Nur Dokument-Operationen.
+ *
+ * Nutzung künftiger V2-Werkzeuge (ab A3):
+ *   doc.transact(() => doc.addElement(line));   // 1 Klick = 1 Undo-Schritt
+ */
+import * as Y from 'yjs';
+import { YjsDocument } from '../../crdt/YjsDocument';
+import type { CADElement, CADLayer, LayoutDefinition, BlockDefinition } from '../../types/cad.types';
+
+export class CADDocument {
+  private readonly ydoc: YjsDocument;
+  private readonly undoManager: Y.UndoManager;
+
+  /** @param ydoc Netzwerkfrei erstellbar (createInMemoryDoc) oder CRDT-verbunden. */
+  constructor(ydoc: YjsDocument) {
+    this.ydoc = ydoc;
+    // Trackt alle Operationen auf Elements + Layers → gemeinsame Undo-Historie.
+    // Blocks/Groups/Configs bewusst NICHT tracken; Layouts (G1) dazu seit Task G1.
+    // captureTimeout 0: KEIN automatisches Mergen zeitnaher Transaktionen —
+    // jede explizite transact() bleibt EIGENER Undo-Schritt (deterministisch für Tools).
+    this.undoManager = new Y.UndoManager([this.ydoc.data.elements, this.ydoc.data.layers, this.ydoc.data.layouts], {
+      captureTimeout: 0,
+    });
+  }
+
+  // ── Lesen ────────────────────────────────────────────────
+
+  /** Ein Element per ID (oder undefined). */
+  getElement(id: string): CADElement | undefined {
+    return this.ydoc.data.elements.get(id);
+  }
+
+  /** Alle Elemente als Array. */
+  getAllElements(): CADElement[] {
+    return Array.from(this.ydoc.data.elements.values());
+  }
+
+  /** Ein Layer per ID (oder undefined). */
+  getLayer(id: string): CADLayer | undefined {
+    return this.ydoc.data.layers.get(id);
+  }
+
+  /** Alle Layer als Array. */
+  getAllLayers(): CADLayer[] {
+    return Array.from(this.ydoc.data.layers.values());
+  }
+
+  // ── Layouts (Task G1) ────────────────────────────────────
+
+  /** Ein Layout per ID (oder undefined). */
+  getLayout(id: string): LayoutDefinition | undefined {
+    return this.ydoc.data.layouts.get(id);
+  }
+
+  /** Alle Layouts als Array. */
+  getAllLayouts(): LayoutDefinition[] {
+    return Array.from(this.ydoc.data.layouts.values());
+  }
+
+  /** Fügt ein Layout hinzu (eigener Undo-Schritt). */
+  addLayout(layout: LayoutDefinition): void {
+    this.transact(() => {
+      this.ydoc.data.layouts.set(layout.id, layout);
+    });
+  }
+
+  /**
+   * Aktualisiert ein Layout: Top-Level-Felder ersetzt, viewport SHALLOW gemergt
+   * (center/scale einzeln änderbar). @throws wenn Layout fehlt.
+   */
+  updateLayout(id: string, patch: Partial<Omit<LayoutDefinition, 'id'>>): void {
+    const existing = this.ydoc.data.layouts.get(id);
+    if (!existing) throw new Error(`updateLayout: Layout '${id}' nicht gefunden`);
+    const merged: LayoutDefinition = {
+      ...existing,
+      ...patch,
+      viewport: patch.viewport
+        ? { ...existing.viewport, ...patch.viewport, center: { ...existing.viewport.center, ...patch.viewport.center } }
+        : existing.viewport,
+    };
+    this.transact(() => {
+      this.ydoc.data.layouts.set(id, merged);
+    });
+  }
+
+  /** Entfernt ein Layout (still bei unbekannter ID, eigener Undo-Schritt). */
+  deleteLayout(id: string): void {
+    this.transact(() => {
+      if (this.ydoc.data.layouts.has(id)) {
+        this.ydoc.data.layouts.delete(id);
+      }
+    });
+  }
+
+  // ── Blöcke (Task G3 — bewusst NICHT undo-getrackt, siehe UndoManager-Kommentar) ──
+
+  /** Eine Blockdefinition per ID (oder undefined). */
+  getBlock(id: string): BlockDefinition | undefined {
+    return this.ydoc.data.blocks.get(id);
+  }
+
+  /** Fügt eine Blockdefinition hinzu (überschreibt gleiche ID). */
+  addBlock(block: BlockDefinition): void {
+    this.ydoc.data.blocks.set(block.id, block);
+  }
+
+
+  /** Fügt einen Layer hinzu (überschreibt gleiche ID, kein Undo-Schritt). */
+  addLayer(layer: CADLayer): void {
+    this.ydoc.data.layers.set(layer.id, layer);
+  }
+
+  /**
+   * Ersetzt das komplette Layer-Set (Task H2: Projekt-Templates).
+   * Bestehende Layer werden entfernt, Template-Layer übernommen.
+   */
+  replaceLayers(layers: CADLayer[]): void {
+    this.transact(() => {
+      for (const id of Array.from(this.ydoc.data.layers.keys())) {
+        this.ydoc.data.layers.delete(id);
+      }
+      for (const l of layers) {
+        this.ydoc.data.layers.set(l.id, l);
+      }
+    });
+  }
+
+  // ── Schreiben ────────────────────────────────────────────
+
+  /** Fügt ein Element hinzu (einzelner Aufruf = eigener Undo-Schritt). */
+  addElement(el: CADElement): void {
+    this.transact(() => {
+      this.ydoc.data.elements.set(el.id, el);
+    });
+  }
+
+  /**
+   * Aktualisiert ein Element: Top-Level-Felder werden ersetzt,
+   * `patch.properties` wird SHALLOW in bestehende Properties gemergt
+   * (Details wie fill/rotation einzeln änderbar, ohne den Rest zu verlieren).
+   * @throws wenn Element nicht existiert
+   */
+  updateElement(id: string, patch: Partial<CADElement>): void {
+    const existing = this.ydoc.data.elements.get(id);
+    if (!existing) throw new Error(`updateElement: Element '${id}' nicht gefunden`);
+    const { properties, ...rest } = patch;
+    const merged: CADElement = {
+      ...existing,
+      ...rest,
+      properties: properties ? { ...existing.properties, ...properties } : existing.properties,
+    };
+    this.transact(() => {
+      this.ydoc.data.elements.set(id, merged);
+    });
+  }
+
+  /** Entfernt mehrere Elemente in EINER Transaktion. Ignoriert unbekannte IDs still. */
+  deleteElements(ids: string[]): void {
+    this.transact(() => {
+      for (const id of ids) {
+        if (this.ydoc.data.elements.has(id)) {
+          this.ydoc.data.elements.delete(id);
+        }
+      }
+    });
+  }
+
+  // ── Transaktion & Undo ───────────────────────────────────
+
+  /** Führt fn aus; ALLE darin getätigten Y-Änderungen werden EIN Undo-Schritt. */
+  transact(fn: () => void): void {
+    this.ydoc.doc.transact(fn);
+  }
+
+  /** Macht den letzten Schritt rückgängig. false wenn nichts da. */
+  undo(): boolean {
+    if (!this.canUndo()) return false;
+    this.undoManager.undo();
+    return true;
+  }
+
+  /** Stellt einen Rückgängig-Schritt wieder her. false wenn nichts da. */
+  redo(): boolean {
+    if (!this.canRedo()) return false;
+    this.undoManager.redo();
+    return true;
+  }
+
+  /** Gibt es etwas zum Rückgängigmachen? */
+  canUndo(): boolean {
+    return this.undoManager.undoStack.length > 0;
+  }
+
+  /** Gibt es etwas zum Wiederherstellen? */
+  canRedo(): boolean {
+    return this.undoManager.redoStack.length > 0;
+  }
+
+  /** Exponiert den Manager (HistoryPanel liest Stacklängen für die UI, A4). */
+  getUndoManager(): Y.UndoManager {
+    return this.undoManager;
+  }
+
+  // ── Subscriptions ────────────────────────────────────────
+
+  /** Benachrichtigung bei JEDEM Doc-Update (inkl. Remote über CRDT). */
+  onChanged(cb: () => void): () => void {
+    return this.ydoc.onChange(cb);
+  }
+}

frontend/src/kernel/document/documentService.ts

@@ -0,0 +1,43 @@
+/**
+ * documentService – Prozessweiter Zugriffspunkt auf das aktive CADDocument.
+ *
+ * Warum: CanvasArea besitzt die V2-Dokumentinstanz (Task A4.1), aber App-Level
+ * UI (HistoryPanel, Tastenkürzel Strg+Z/Y) benötigt Zugriff OHNE prop-
+ * threading durch die God-Component. Dieser Service ist die bewusste,
+ * dokumentierte Ausnahme von der Reinheitsregel — nur EINE Instanz aktiv.
+ *
+ * Setzen/Entfernen übernimmt CanvasArea im Mount-/Cleanup-Zyklus.
+ */
+import type { CADDocument } from './CADDocument';
+
+type Listener = () => void;
+
+let activeDoc: CADDocument | null = null;
+const listeners = new Set<Listener>();
+
+/** Registriert das aktive Dokument (CanvasArea-Mount). */
+export function setActiveDocument(doc: CADDocument | null): void {
+  activeDoc = doc;
+  listeners.forEach((l) => l());
+}
+
+/** Aktives Dokument oder null (z.B. wenn Flag aus / Canvas unmounted). */
+export function getActiveDocument(): CADDocument | null {
+  return activeDoc;
+}
+
+/** Änderungsabonnement (für React-Hooks). Liefert Unsubscribe. */
+export function onActiveDocumentChanged(cb: Listener): () => void {
+  listeners.add(cb);
+  return () => listeners.delete(cb);
+}
+
+/** Bequemlichkeit: globaler Undo am aktiven Dokument. false wenn kein Doc/Stack leer. */
+export function undoActive(): boolean {
+  return activeDoc?.undo() ?? false;
+}
+
+/** Bequemlichkeit: globales Redo am aktiven Dokument. */
+export function redoActive(): boolean {
+  return activeDoc?.redo() ?? false;
+}

frontend/src/kernel/featureFlags.ts

@@ -0,0 +1,23 @@
+/**
+ * featureFlags – Zentrale Feature-Schalter (Task A4.14).
+ *
+ * V2_TOOLS_ENABLED: Ab v2.0 ist der Plugin-first-Pfad (InteractionDispatcher,
+ * CADDocument, dynamisches Ribbon, V2HistoryPanel) STANDARDMÄSSIG AKTIV.
+ * Opt-out für den Legacy-Pfad: VITE_TOOL_DISPATCHER=legacy setzen.
+ *
+ * Begründung Historie: Vor A4.14 war V2 opt-in ('v2' explizit nötig), weil
+ * noch keine Browser-Verifikation existierte. Die Playwright-Verifikation
+ * (phase-a-verify.test.ts, grün) hat das Risiko entwertet.
+ */
+
+/** Ist der V2-Werkzeugpfad (Dispatcher/CADDocument) aktiv? Default: ja. */
+export const V2_TOOLS_ENABLED: boolean =
+  import.meta.env.VITE_TOOL_DISPATCHER !== 'legacy';
+
+/**
+ * Task C4: Pixi als Primär-Renderer für V2-Elemente (Overlay über Legacy).
+ * Default: ja (durch phase-a-verify E2E abgesichert).
+ * Opt-out: VITE_USE_PIXI=false.
+ */
+export const USE_PIXI_RENDERER: boolean =
+  import.meta.env.VITE_USE_PIXI !== 'false';

frontend/src/plugins/PluginRegistry.ts

@@ -9,14 +9,29 @@ import type {
   ToolExtension,
   CommandExtension,
   ImportExportExtension,
+  // API v2 (Task A1):
+  PluginV2,
+  ToolExtensionV2,
+  PanelExtension,
+  LibraryProviderExtension,
 } from './types';
 
+/** Interner Zustand eines registrierten V2-Plugins. */
+interface PluginStateV2 {
+  plugin: PluginV2;
+  enabled: boolean;
+  loaded: boolean;
+}
+
 class PluginRegistryClass {
   private plugins = new Map<string, Plugin>();
   private states = new Map<string, PluginState>();
   private context: PluginContext | null = null;
   private listeners = new Set<() => void>();
 
+  // ── API v2 (Task A1) ─────────────────────────────────────
+  private v2Plugins = new Map<string, PluginStateV2>();
+
   /** Set the plugin context (called once on app init) */
   setContext(ctx: PluginContext) {
     this.context = ctx;
@@ -164,6 +179,96 @@ class PluginRegistryClass {
         this.enable(id);
       }
     }
+    for (const [id, state] of this.v2Plugins) {
+      if (state.plugin.manifest.enabledByDefault && !state.enabled) {
+        this.enableV2(id);
+      }
+    }
+  }
+
+  // ═══════════ API v2 (Task A1 — additiv) ═══════════
+
+  /** Registriert ein V2-Plugin. Doppelte IDs werden verworfen (Warnung). */
+  registerV2(plugin: PluginV2): void {
+    const { id } = plugin.manifest;
+    if (this.v2Plugins.has(id)) {
+      console.warn(`[PluginRegistry] V2-Plugin '${id}' bereits registriert – verworfen`);
+      return;
+    }
+    this.v2Plugins.set(id, {
+      plugin,
+      enabled: false,
+      loaded: false,
+    });
+    this.notify();
+  }
+
+  /** Entfernt ein V2-Plugin (ruft onDestroy wenn geladen). */
+  unregisterV2(pluginId: string): void {
+    const state = this.v2Plugins.get(pluginId);
+    if (!state) return;
+    if (state.loaded) state.plugin.onDestroy?.();
+    this.v2Plugins.delete(pluginId);
+    this.notify();
+  }
+
+  /** Aktiviert ein V2-Plugin (onInit einmalig, dann onActivate). */
+  enableV2(pluginId: string): void {
+    const state = this.v2Plugins.get(pluginId);
+    if (!state || state.enabled) return;
+    state.enabled = true;
+    if (!state.loaded) {
+      state.plugin.onInit?.();
+      state.loaded = true;
+    }
+    state.plugin.onActivate?.();
+    this.notify();
+  }
+
+  /** Deaktiviert ein V2-Plugin. */
+  disableV2(pluginId: string): void {
+    const state = this.v2Plugins.get(pluginId);
+    if (!state || !state.enabled) return;
+    state.enabled = false;
+    state.plugin.onDeactivate?.();
+    this.notify();
+  }
+
+  /** Ist dieses V2-Plugin aktiv? */
+  isV2Enabled(pluginId: string): boolean {
+    return this.v2Plugins.get(pluginId)?.enabled ?? false;
+  }
+
+  /** Alle Tools aus AKTIVEN V2-Plugins (flach über alle Plugins). */
+  getToolsV2(): ToolExtensionV2[] {
+    const tools: ToolExtensionV2[] = [];
+    for (const state of this.v2Plugins.values()) {
+      if (state.enabled && state.plugin.tools) tools.push(...state.plugin.tools);
+    }
+    return tools;
+  }
+
+  /** Ein bestimmtes V2-Tool per ID (nur aus aktiven Plugins). */
+  getToolV2(toolId: string): ToolExtensionV2 | undefined {
+    return this.getToolsV2().find((t) => t.manifest.id === toolId);
+  }
+
+  /** Alle Panels aktiver V2-Plugins. */
+  getPanels(): PanelExtension[] {
+    const panels: PanelExtension[] = [];
+    for (const state of this.v2Plugins.values()) {
+      if (state.enabled && state.plugin.panels) panels.push(...state.plugin.panels);
+    }
+    return panels;
+  }
+
+  /** Alle Library-Provider aktiver V2-Plugins. */
+  getLibraryProviders(): LibraryProviderExtension[] {
+    const providers: LibraryProviderExtension[] = [];
+    for (const state of this.v2Plugins.values()) {
+      if (state.enabled && state.plugin.libraryProviders) providers.push(...state.plugin.libraryProviders);
+    }
+    return providers;
   }
 }
 

frontend/src/plugins/builtin/core-annotate/index.ts

@@ -0,0 +1,207 @@
+/**
+ * core-annotate – Built-in V2-Plugin (Task A4.4).
+ *
+ * Werkzeuge: text (Platzierung — Inhalt via InlineTextEditor/PropertiesPanel,
+ * Bestandskanal onTextEdit bleibt), dimension (2-Punkt linear), leader
+ * (2-Punkt Pfeil+Label).
+ */
+import type { PluginV2, ToolExtensionV2, FullToolContext } from '../../types';
+import type { CADElement } from '../../../types/cad.types';
+import type { Pt } from '../../../tools/modification/geometry';
+
+const uid = (prefix: string): string =>
+  `${prefix}_${Date.now().toString(36)}_${Math.random().toString(36).slice(2, 9)}`;
+
+/** Gemeinsamer 2-Punkt-Sitzungsstart für dimension/leader. */
+let twoPointStart: Pt | null = null;
+
+function optsOf(ctx: FullToolContext): { stroke: string; layerId: string } {
+  return {
+    stroke: (ctx.options.strokeColor as string | undefined) ?? '#e0e0e0',
+    layerId: (ctx.options.layerId as string | undefined) ?? 'layer-0',
+  };
+}
+
+function buildDimension(start: Pt, end: Pt, ctx: FullToolContext): CADElement {
+  const o = optsOf(ctx);
+  return {
+    id: uid('dim'),
+    type: 'dimension',
+    layerId: o.layerId,
+    x: (start.x + end.x) / 2,
+    y: (start.y + end.y) / 2,
+    width: Math.hypot(end.x - start.x, end.y - start.y), // Legacy: dist als Breite
+    height: 20,
+    properties: { x1: start.x, y1: start.y, x2: end.x, y2: end.y },
+  } as unknown as CADElement;
+}
+
+function buildLeader(start: Pt, end: Pt, ctx: FullToolContext): CADElement {
+  const o = optsOf(ctx);
+  return {
+    id: uid('leader'),
+    type: 'leader',
+    layerId: o.layerId,
+    x: end.x,
+    y: end.y,
+    width: Math.abs(end.x - start.x),
+    height: Math.abs(end.y - start.y),
+    properties: { x1: start.x, y1: start.y, x2: end.x, y2: end.y, text: '', fontSize: 12, stroke: o.stroke, strokeWidth: 1 },
+  } as unknown as CADElement;
+}
+
+/** Generischer 2-Punkt-Annotate-Fluss (down→Preview→up commit). */
+function make2PointAnnotate(
+  id: 'dimension' | 'leader',
+  label: string,
+  icon: string,
+  build: (a: Pt, b: Pt, ctx: FullToolContext) => CADElement,
+): ToolExtensionV2 {
+  return {
+    manifest: { id, label, icon, ribbonTab: 'format', tags: ['basic'] },
+    optionsSchema: [{ key: 'strokeColor', label: 'Farbe', type: 'color' }],
+    handlers: {
+      down(e, ctx) {
+        twoPointStart = e.world;
+        ctx.setStatus(`${label}: Startpunkt gesetzt – Ende wählen`);
+      },
+      move(e, ctx) {
+        if (!twoPointStart) return;
+        ctx.setPreview?.(build(twoPointStart, e.world, ctx as FullToolContext));
+      },
+      up(e, ctx) {
+        const c = ctx as FullToolContext;
+        if (!twoPointStart || !c.doc) { twoPointStart = null; return; }
+        const el = build(twoPointStart, e.world, c);
+        c.doc.transact(() => c.doc!.addElement(el));
+        twoPointStart = null;
+        ctx.setPreview?.(null);
+        ctx.setStatus(`${label} erstellt (${el.id})`);
+      },
+      cancel(ctx) {
+        twoPointStart = null;
+        ctx.setPreview?.(null);
+        ctx.setStatus(`${label} abgebrochen`);
+      },
+    },
+  };
+}
+
+/**
+ * text-Werkzeug (A4.4): Klick platziert Textelement mit leerem Inhalt;
+ * Bearbeitung läuft über den bestehenden InlineTextEditor/onTextEdit-Kanal.
+ */
+export const textTool: ToolExtensionV2 = {
+  manifest: {
+    id: 'text',
+    label: 'Text',
+    icon: 'T',
+    ribbonTab: 'format',
+    tags: ['basic'],
+    description: 'Text platzieren und über Editor beschriften',
+  },
+  optionsSchema: [{ key: 'fontSize', label: 'Größe', type: 'number', min: 6, max: 72 }],
+  handlers: {
+    down(e, ctx) {
+      const c = ctx as FullToolContext;
+      if (!c.doc) return;
+      const layerId = (c.options.layerId as string | undefined) ?? 'layer-0';
+      const fontSize = (c.options.fontSize as number | undefined) ?? 12;
+      const el = {
+        id: uid('text'),
+        type: 'text',
+        layerId,
+        x: e.world.x,
+        y: e.world.y,
+        width: 100,
+        height: 20,
+        properties: { text: '', fontSize },
+      } as unknown as CADElement;
+      c.doc.transact(() => c.doc!.addElement(el));
+      ctx.setStatus(`Text platziert (${el.id}) – now via Editor`);
+    },
+  },
+};
+
+export const dimensionTool: ToolExtensionV2 = make2PointAnnotate('dimension', 'Bemaßung', '\u2194', buildDimension);
+export const leaderTool: ToolExtensionV2 = make2PointAnnotate('leader', 'Leader', '\u21b1', buildLeader);
+
+/** V2-Plugin: Beschriftung/Bemaßung (A4.4). */
+// ─────────────────────────────────────────────────────────────
+// Task D4: MTEXT — Mehrzeiliger Text mit optionalem Rahmen.
+// Klick platziert Text (Inhalt aus Options, Zeilenumbrüche erhalten),
+// frame-Option erzeugt ein rect in derselben Transaktion (1 Undo).
+// ─────────────────────────────────────────────────────────────
+
+export const mtextTool: ToolExtensionV2 = {
+  manifest: {
+    id: 'mtext',
+    label: 'Mehrzeilentext',
+    icon: '¶',
+    ribbonTab: 'format',
+    tags: ['basic'],
+    description: 'Mehrzeiligen Text platzieren (Rahmen optional, Task D4)',
+  },
+  optionsSchema: [
+    { key: 'text', label: 'Text', type: 'text' },
+    { key: 'fontSize', label: 'Größe', type: 'number', min: 6, max: 72 },
+    { key: 'frame', label: 'Rahmen', type: 'checkbox' },
+  ],
+  handlers: {
+    down(e, ctx) {
+      const c = ctx as FullToolContext;
+      if (!c.doc) return;
+      const layerId = (c.options.layerId as string | undefined) ?? 'layer-0';
+      const text = (c.options.text as string | undefined) ?? '';
+      const fontSize = (c.options.fontSize as number | undefined) ?? 12;
+      const frame = (c.options.frame as boolean | undefined) ?? false;
+      // Newline ohne Escape-Probleme: charCode 10
+      const NL = String.fromCharCode(10);
+      const lines = text.split(NL);
+      const lineCount = Math.max(1, lines.length);
+      const maxLen = lines.reduce((m, l) => Math.max(m, l.length), 0);
+      const textW = maxLen * fontSize * 0.6;
+      const textH = lineCount * fontSize * 1.4;
+      const els: CADElement[] = [{
+        id: uid('mtext'),
+        type: 'text',
+        layerId,
+        x: e.world.x,
+        y: e.world.y,
+        width: textW,
+        height: textH,
+        properties: { text, fontSize, mtext: true },
+      } as unknown as CADElement];
+      if (frame) {
+        const pad = fontSize * 0.4;
+        els.push({
+          id: uid('mtextframe'),
+          type: 'rect',
+          layerId,
+          x: e.world.x,
+          y: e.world.y,
+          width: textW + pad * 2,
+          height: textH + pad * 2,
+          properties: { stroke: '#9aa0a6', strokeWidth: 1, fill: 'none' },
+        } as unknown as CADElement);
+      }
+      c.doc.transact(() => {
+        for (const el of els) c.doc!.addElement(el);
+      });
+      ctx.setStatus(`Mehrzeilentext platziert (${lineCount} Zeile(n)${frame ? ', mit Rahmen' : ''})`);
+    },
+  },
+};
+
+export const coreAnnotatePlugin: PluginV2 = {
+  manifest: {
+    id: 'core-annotate',
+    name: 'Beschriftung (Kern)',
+    version: '1.1.0',
+    author: 'web-cad team',
+    description: 'Text, Bemaßung, Leader (V2).',
+    category: 'tools',
+    enabledByDefault: true,
+  },
+  tools: [textTool, dimensionTool, leaderTool, mtextTool],
+};

frontend/src/plugins/builtin/core-drawing/index.ts

@@ -0,0 +1,905 @@
+/**
+ * core-drawing – Built-in V2-Plugin (Task A3 Pilot).
+ *
+ * Werkzeuge: line (Migrations-Pilot aus dem Legacy-Switch).
+ * Elemente werden über CADDocument committed → kollaborativ korrektes Undo.
+ *
+ * Sitzungszustand (Startpunkt der aktuellen Linie) lebt als Modul-Member,
+ * NICHT in options: Options sind geteilter UI-Store-Zustand.
+ */
+import type { PluginV2, ToolExtensionV2, FullToolContext } from '../../types';
+import type { CADElement } from '../../../types/cad.types';
+import type { Pt } from '../../../tools/modification/geometry';
+
+const uid = (prefix: string): string =>
+  `${prefix}_${Date.now().toString(36)}_${Math.random().toString(36).slice(2, 9)}`;
+
+/** Startpunkt der laufenden Linie (nur innerhalb einer down→up-Sitzung gesetzt). */
+let lineStart: Pt | null = null;
+/** Startpunkt des laufenden Rechtecks (A4.2). */
+let rectStart: Pt | null = null;
+/** Zentrum des laufenden Kreises (A4.3). */
+let circleCenter: Pt | null = null;
+/** Laufender Bogen: Phase 0=nichts, 1=Zentrum gesetzt, 2=Radius+Startwinkel gesetzt. */
+let arcPhase = 0;
+let arcCenter: Pt | null = null;
+let arcStartPt: Pt | null = null;
+/** Laufende Polyline/Polygon-Punkte; Commit per ENTER. */
+let polyPoints: Pt[] = [];
+/** Laufende RevCloud-Punkte (A4.5); Commit per ENTER. */
+let cloudPoints: Pt[] = [];
+
+function optsOf(ctx: FullToolContext): { stroke: string; layerId: string } {
+  return {
+    stroke: (ctx.options.strokeColor as string | undefined) ?? '#e0e0f0',
+    layerId: (ctx.options.layerId as string | undefined) ?? 'layer-0',
+  };
+}
+
+function buildLine(start: Pt, end: Pt, ctx: FullToolContext): CADElement {
+  const stroke = (ctx.options.strokeColor as string | undefined) ?? '#e0e0f0';
+  const layerId = (ctx.options.layerId as string | undefined) ?? 'layer-0';
+  return {
+    id: uid('line'),
+    type: 'line',
+    layerId,
+    x: (start.x + end.x) / 2,
+    y: (start.y + end.y) / 2,
+    width: Math.abs(end.x - start.x),
+    height: Math.abs(end.y - start.y),
+    properties: { x1: start.x, y1: start.y, x2: end.x, y2: end.y, stroke, strokeWidth: 1 },
+  } as unknown as CADElement;
+}
+
+function buildRect(cornerA: Pt, cornerB: Pt, ctx: FullToolContext): CADElement {
+  const stroke = (ctx.options.strokeColor as string | undefined) ?? '#e0e0f0';
+  const layerId = (ctx.options.layerId as string | undefined) ?? 'layer-0';
+  const minX = Math.min(cornerA.x, cornerB.x);
+  const minY = Math.min(cornerA.y, cornerB.y);
+  const w = Math.abs(cornerB.x - cornerA.x);
+  const h = Math.abs(cornerB.y - cornerA.y);
+  return {
+    id: uid('rect'),
+    type: 'rect',
+    layerId,
+    x: minX + w / 2,          // BBox-Zentrum (Legacy-Konvention)
+    y: minY + h / 2,
+    width: w,
+    height: h,
+    properties: { stroke, strokeWidth: 1 },
+  } as unknown as CADElement;
+}
+
+/**
+ * line-Werkzeug: down setzt Startpunkt, move zeigt Live-Vorschau,
+ * up committet via doc.transact (1 Linie = 1 Undo-Schritt).
+ */
+export const lineTool: ToolExtensionV2 = {
+  manifest: {
+    id: 'line',
+    label: 'Linie',
+    icon: '\u2571',
+    ribbonTab: 'canvas',
+    tags: ['basic'],
+    description: 'Zeichnet eine Linie (Klick Start, Klick Ende)',
+  },
+  optionsSchema: [
+    { key: 'strokeColor', label: 'Farbe', type: 'color' },
+  ],
+  handlers: {
+    down(e, ctx) {
+      lineStart = e.world;
+      ctx.setStatus(`Linie ab (${lineStart.x.toFixed(0)}, ${lineStart.y.toFixed(0)}) – Ende wählen`);
+    },
+    move(e, ctx) {
+      if (!lineStart) return;
+      ctx.setPreview?.(buildLine(lineStart, e.world, ctx));
+    },
+    up(e, ctx) {
+      const c = ctx as FullToolContext;
+      if (!lineStart || !c.doc) {
+        lineStart = null;
+        return;
+      }
+      const el = buildLine(lineStart, e.world, c);
+      c.doc.transact(() => {
+        // addElement öffnet inneres transact — Yjs verschachtelt sie → EIN Undo-Schritt
+        c.doc!.addElement(el);
+      });
+      lineStart = null;
+      ctx.setPreview?.(null);
+      ctx.setStatus(`Linie erstellt (${el.id})`);
+    },
+    cancel(ctx) {
+      lineStart = null;
+      ctx.setPreview?.(null);
+      ctx.setStatus('Linie abgebrochen');
+    },
+  },
+};
+
+/**
+ * rect-Werkzeug (A4.2): down setzt Ecke, move zeigt BBox-Vorschau,
+ * up committet via doc.transact. Portiert aus Legacy case 'rect'
+ * (BBox-Konvention: x/y = Zentrum, width/height absolut).
+ */
+export const rectTool: ToolExtensionV2 = {
+  manifest: {
+    id: 'rect',
+    label: 'Rechteck',
+    icon: '\u25ad',
+    ribbonTab: 'canvas',
+    tags: ['basic'],
+    description: 'Zieht ein Rechteck auf (Klick Ecke, Klick Gegenecke)',
+  },
+  optionsSchema: [
+    { key: 'strokeColor', label: 'Farbe', type: 'color' },
+  ],
+  handlers: {
+    down(e, ctx) {
+      rectStart = e.world;
+      ctx.setStatus(`Rechteck ab (${rectStart.x.toFixed(0)}, ${rectStart.y.toFixed(0)}) – Gegenecke wählen`);
+    },
+    move(e, ctx) {
+      if (!rectStart) return;
+      ctx.setPreview?.(buildRect(rectStart, e.world, ctx));
+    },
+    up(e, ctx) {
+      const c = ctx as FullToolContext;
+      if (!rectStart || !c.doc) {
+        rectStart = null;
+        return;
+      }
+      const el = buildRect(rectStart, e.world, c);
+      c.doc.transact(() => {
+        c.doc!.addElement(el);
+      });
+      rectStart = null;
+      ctx.setPreview?.(null);
+      ctx.setStatus(`Rechteck erstellt (${el.id})`);
+    },
+    cancel(ctx) {
+      rectStart = null;
+      ctx.setPreview?.(null);
+      ctx.setStatus('Rechteck abgebrochen');
+    },
+  },
+};
+
+/**
+ * circle-Werkzeug (A4.3): Zentrum→Radius wie Legacy (Radius = Distanz).
+ */
+export const circleTool: ToolExtensionV2 = {
+  manifest: {
+    id: 'circle', label: 'Kreis', icon: '\u25cb', ribbonTab: 'canvas', tags: ['basic'],
+    description: 'Kreis: Zentrum klicken, Radius ziehen',
+  },
+  optionsSchema: [{ key: 'strokeColor', label: 'Farbe', type: 'color' }],
+  handlers: {
+    down(e, ctx) { circleCenter = e.world; ctx.setStatus('Kreiszentrum gesetzt – Radius ziehen'); },
+    move(e, ctx) {
+      if (!circleCenter) return;
+      const r = Math.hypot(e.world.x - circleCenter.x, e.world.y - circleCenter.y);
+      ctx.setPreview?.(buildCircle(circleCenter, r, ctx));
+    },
+    up(e, ctx) {
+      const c = ctx as FullToolContext;
+      if (!circleCenter || !c.doc) { circleCenter = null; return; }
+      const r = Math.hypot(e.world.x - circleCenter.x, e.world.y - circleCenter.y);
+      const el = buildCircle(circleCenter, r, c);
+      c.doc.transact(() => c.doc!.addElement(el));
+      circleCenter = null;
+      ctx.setPreview?.(null);
+      ctx.setStatus(`Kreis erstellt (${el.id})`);
+    },
+    cancel(ctx) { circleCenter = null; ctx.setPreview?.(null); ctx.setStatus('Kreis abgebrochen'); },
+  },
+};
+
+/**
+ * arc-Werkzeug (A4.3): 3-Klick wie Legacy — Zentrum, Startpunkt (Radius+
+ * Startwinkel), Endpunkt (Endwinkel). Winkel in Grad CCW.
+ */
+export const arcTool: ToolExtensionV2 = {
+  manifest: {
+    id: 'arc', label: 'Bogen', icon: '\u2322', ribbonTab: 'canvas', tags: ['basic'],
+    description: 'Bogen: Zentrum, Startpunkt, Endpunkt',
+  },
+  optionsSchema: [{ key: 'strokeColor', label: 'Farbe', type: 'color' }],
+  handlers: {
+    down(e, ctx) {
+      const c = ctx as FullToolContext;
+      if (arcPhase === 0) {
+        arcCenter = e.world;
+        arcPhase = 1;
+        ctx.setStatus('Bogenzentrum gesetzt \u2013 Startpunkt w\u00e4hlen');
+      } else if (arcPhase === 1) {
+        arcStartPt = e.world;
+        arcPhase = 2;
+        ctx.setStatus('Bogen: Endpunkt w\u00e4hlen');
+      } else if (arcPhase === 2 && arcCenter && arcStartPt) {
+        // Dritter Klick committet (klick-progressiv wie Legacy — up feuert im
+        // echten Browser immer direkt nach down, darf deshalb NICHT committen)
+        if (!c.doc) { arcPhase = 0; arcCenter = null; arcStartPt = null; return; }
+        const el = buildArc(arcCenter, arcStartPt, e.world, c);
+        c.doc.transact(() => c.doc!.addElement(el));
+        ctx.setPreview?.(null);
+        ctx.setStatus(`Bogen erstellt (${el.id})`);
+        arcPhase = 0;
+        arcCenter = null;
+        arcStartPt = null;
+      }
+    },
+    move(e, ctx) {
+      if (arcPhase === 1 && arcCenter) {
+        const r = Math.hypot(e.world.x - arcCenter.x, e.world.y - arcCenter.y);
+        // Vollkreis-Guide in Phasen-Preview (Legacy-Konvention)
+        ctx.setPreview?.(buildArcFullGuide(arcCenter, r, ctx));
+      } else if (arcPhase === 2 && arcCenter && arcStartPt) {
+        ctx.setPreview?.(buildArc(arcCenter, arcStartPt, e.world, ctx));
+      }
+    },
+    cancel(ctx) {
+      arcPhase = 0; arcCenter = null; arcStartPt = null;
+      ctx.setPreview?.(null); ctx.setStatus('Bogen abgebrochen');
+    },
+  },
+};
+
+/**
+ * polyline-Werkzeug (A4.3): Mehrklick fügt Punkte; ENTER committet ab 2 Punkten.
+ */
+export const polylineTool: ToolExtensionV2 = makePolyTool('polyline', 'Polylinie', 2, '\u2500');
+
+/**
+ * polygon-Werkzeug (A4.3): wie Polylinie, aber geschlossen; ENTER ab 3 Punkten.
+ */
+export const polygonTool: ToolExtensionV2 = makePolyTool('polygon', 'Polygon', 3, '\u2b21');
+
+function makePolyTool(type: 'polyline' | 'polygon', label: string, minPoints: number, icon: string): ToolExtensionV2 {
+  return {
+    manifest: { id: type, label, icon, ribbonTab: 'canvas', tags: ['basic'], description: `${label}: Punkte klicken, ENTER beendet` },
+    optionsSchema: [{ key: 'strokeColor', label: 'Farbe', type: 'color' }],
+    handlers: {
+      down(e, ctx) {
+        polyPoints.push(e.world);
+        if (!isPolyType(type)) return;
+        ctx.setStatus(`${label}: ${polyPoints.length} Punkte – ENTER beendet`);
+      },
+      move(e, ctx) {
+        if (polyPoints.length === 0) return;
+        const pts = [...polyPoints, e.world];
+        ctx.setPreview?.(buildPoly(type, pts, ctx));
+      },
+      up() { /* commit nur via ENTER */ },
+      key(e, ctx) {
+        if (e.key !== 'Enter') return false;
+        if (polyPoints.length < minPoints) {
+          ctx.setStatus(`${label}: mindestens ${minPoints} Punkte nötig`);
+          return true; // konsumiert
+        }
+        const el = buildPoly(type, polyPoints, ctx as FullToolContext);
+        const doc = (ctx as FullToolContext).doc;
+        if (!doc) { resetPoly(); return true; }
+        doc.transact(() => doc.addElement(el));
+        resetPoly();
+        ctx.setPreview?.(null);
+        ctx.setStatus(`${label} erstellt (${el.id})`);
+        return true;
+      },
+      cancel(ctx) {
+        resetPoly();
+        ctx.setPreview?.(null);
+        ctx.setStatus(`${label} abgebrochen`);
+      },
+    },
+  };
+}
+
+function isPolyType(t: string): boolean {
+  return t === 'polyline' || t === 'polygon';
+}
+
+function resetPoly(): void {
+  polyPoints = [];
+}
+
+// ─── Build-Helfer A4.3 ───────────────────────────────────────
+
+function buildCircle(center: Pt, radius: number, ctx: FullToolContext): CADElement {
+  const o = optsOf(ctx);
+  return {
+    id: uid('circle'), type: 'circle', layerId: o.layerId,
+    x: center.x, y: center.y, width: radius * 2, height: radius * 2,
+    properties: { radius, stroke: o.stroke, strokeWidth: 1 },
+  } as unknown as CADElement;
+}
+
+function anglesOf(center: Pt, start: Pt, end: Pt): { radius: number; startAngle: number; endAngle: number } {
+  const radius = Math.hypot(start.x - center.x, start.y - center.y);
+  const startAngle = (Math.atan2(start.y - center.y, start.x - center.x) * 180) / Math.PI;
+  const endAngle = (Math.atan2(end.y - center.y, end.x - center.x) * 180) / Math.PI;
+  return { radius, startAngle, endAngle };
+}
+
+function buildArc(center: Pt, startPt: Pt, endPt: Pt, ctx: FullToolContext): CADElement {
+  const o = optsOf(ctx);
+  const a = anglesOf(center, startPt, endPt);
+  return {
+    id: uid('arc'), type: 'arc', layerId: o.layerId,
+    x: center.x, y: center.y, width: a.radius * 2, height: a.radius * 2,
+    properties: { radius: a.radius, startAngle: a.startAngle, endAngle: a.endAngle, stroke: o.stroke, strokeWidth: 1 },
+  } as unknown as CADElement;
+}
+
+function buildArcFullGuide(center: Pt, radius: number, ctx: FullToolContext): CADElement {
+  // Vollkreis-Vorschau als Radien-Leitfaden (Legacy-Verhalten Phase 1)
+  const o = optsOf(ctx);
+  return {
+    id: uid('arc'), type: 'circle', layerId: o.layerId,
+    x: center.x, y: center.y, width: radius * 2, height: radius * 2,
+    properties: { radius, stroke: o.stroke, strokeWidth: 1, guideOnly: true },
+  } as unknown as CADElement;
+}
+
+function buildPoly(type: 'polyline' | 'polygon', pts: Pt[], ctx: FullToolContext): CADElement {
+  const o = optsOf(ctx);
+  const xs = pts.map((p) => p.x);
+  const ys = pts.map((p) => p.y);
+  return {
+    id: uid(type), type, layerId: o.layerId,
+    x: (Math.min(...xs) + Math.max(...xs)) / 2,
+    y: (Math.min(...ys) + Math.max(...ys)) / 2,
+    width: Math.max(...xs) - Math.min(...xs),
+    height: Math.max(...ys) - Math.min(...ys),
+    properties: { points: pts.map((p) => ({ x: p.x, y: p.y })), stroke: o.stroke, strokeWidth: 1 },
+  } as unknown as CADElement;
+}
+
+/**
+ * revcloud-Werkzeug (A4.5): Mehrklick-Revisionswolke wie Poly-Muster;
+ * ENTER committet ab 3 Punkten. Legacy-Konvention: arcHeight 8.
+ */
+export const revcloudTool: ToolExtensionV2 = {
+  manifest: {
+    id: 'revcloud', label: 'RevCloud', icon: '\u2611', ribbonTab: 'format', tags: ['pro'],
+    description: 'Revisionswolke: Punkte klicken, ENTER beendet',
+  },
+  optionsSchema: [{ key: 'strokeColor', label: 'Farbe', type: 'color' }],
+  handlers: {
+    down(e, ctx) {
+      cloudPoints.push(e.world);
+      ctx.setStatus(`RevCloud: ${cloudPoints.length} Punkte \u2013 ENTER beendet`);
+    },
+    move(e, ctx) {
+      if (cloudPoints.length === 0) return;
+      ctx.setPreview?.(buildRevCloud([...cloudPoints, e.world], ctx));
+    },
+    up() { /* commit via ENTER */ },
+    key(e, ctx) {
+      if (e.key !== 'Enter') return false;
+      if (cloudPoints.length < 3) {
+        ctx.setStatus('RevCloud: mindestens 3 Punkte n\u00f6tig');
+        return true;
+      }
+      const c = ctx as FullToolContext;
+      if (!c.doc) { cloudPoints = []; return true; }
+      const el = buildRevCloud(cloudPoints, c);
+      c.doc.transact(() => c.doc!.addElement(el));
+      cloudPoints = [];
+      ctx.setPreview?.(null);
+      ctx.setStatus(`RevCloud erstellt (${el.id})`);
+      return true;
+    },
+    cancel(ctx) {
+      cloudPoints = [];
+      ctx.setPreview?.(null);
+      ctx.setStatus('RevCloud abgebrochen');
+    },
+  },
+};
+
+function buildRevCloud(pts: Pt[], ctx: FullToolContext): CADElement {
+  const o = optsOf(ctx);
+  const xs = pts.map((p) => p.x);
+  const ys = pts.map((p) => p.y);
+  return {
+    id: uid('revcloud'), type: 'revcloud', layerId: o.layerId,
+    x: (Math.min(...xs) + Math.max(...xs)) / 2,
+    y: (Math.min(...ys) + Math.max(...ys)) / 2,
+    width: Math.max(...xs) - Math.min(...xs),
+    height: Math.max(...ys) - Math.min(...ys),
+    properties: { points: pts.map((p) => ({ x: p.x, y: p.y })), arcHeight: 8, fill: 'none', stroke: '#e0e0e0', strokeWidth: 1.5 },
+  } as unknown as CADElement;
+}
+
+/** V2-Plugin: Kern-Zeichenwerkzeuge (A4.x schrittweise migriert). */
+// ─────────────────────────────────────────────────────────────
+// Task D1: Ellipse (3-Klick: Zentrum→RadiusX→RadiusY) +
+// Ellipsenbogen via startAngle/endAngle-Options.
+// ─────────────────────────────────────────────────────────────
+
+/** Ellipsen-Sitzung: Phase 0=nichts, 1=Zentrum, 2=RadiusX fixiert. */
+let ellipsePhase = 0;
+let ellipseCenter: Pt | null = null;
+let ellipseRadiusX = 0;
+/** Rotation aus der Klick2-Zugrichtung (Grad, 0°=+x, CW-positiv). */
+let ellipseRotationDeg = 0;
+
+/**
+ * Ellipse als Polyline-Approximation (F5-Parser-Konvention):
+ * Voll-Ellipse → 64 Punkte geschlossen (polygon), Bogen → proportional
+ * offene Polyline. rotation aus der Klick2-Zugrichtung (Grad, 0°=+x).
+ */
+function buildEllipse(
+  cx: number,
+  cy: number,
+  rx: number,
+  ry: number,
+  rotationDeg: number,
+  ctx: FullToolContext,
+  startAngle = 0,
+  endAngle = 360,
+): CADElement {
+  const stroke = (ctx.options.strokeColor as string | undefined) ?? '#e0e0f0';
+  const layerId = (ctx.options.layerId as string | undefined) ?? 'layer-0';
+  const phi = (rotationDeg * Math.PI) / 180;
+  const cosP = Math.cos(phi), sinP = Math.sin(phi);
+  const FULL = 360;
+  const span = Math.min(endAngle, FULL) - Math.min(startAngle, FULL);
+  const isFull = span >= FULL - 0.001 || span <= 0.001;
+  const n = Math.max(2, Math.round(64 * (Math.max(span, 1) / FULL)));
+  const pts: Pt[] = [];
+  for (let i = 0; i < n; i++) {
+    const t = ((startAngle + (span * i) / (isFull ? n : (n - 1))) * Math.PI) / 180;
+    const x = rx * Math.cos(t);
+    const y = ry * Math.sin(t);
+    pts.push({
+      x: cx + x * cosP - y * sinP,
+      y: cy + x * sinP + y * cosP,
+    });
+  }
+  const xs = pts.map((p) => p.x), ys = pts.map((p) => p.y);
+  const minX = Math.min(...xs), minY = Math.min(...ys);
+  const type = isFull ? 'polygon' : 'polyline';
+  return {
+    id: uid('ellipse'),
+    type,
+    layerId,
+    x: minX + (Math.max(...xs) - minX) / 2,
+    y: minY + (Math.max(...ys) - minY) / 2,
+    width: Math.max(...xs) - minX,
+    height: Math.max(...ys) - minY,
+    properties: {
+      points: pts,
+      stroke,
+      strokeWidth: 1,
+      cx, cy, rx, ry,
+      rotation: rotationDeg,
+      ...(isFull ? {} : { startAngle, endAngle }),
+    },
+  } as unknown as CADElement;
+}
+
+export const ellipseTool: ToolExtensionV2 = {
+  manifest: {
+    id: 'ellipse',
+    label: 'Ellipse',
+    icon: '\u2b2d',
+    ribbonTab: 'canvas',
+    tags: ['basic'],
+    description: 'Ellipse zeichnen: Zentrum klicken, RadiusX, RadiusY (Bogen via Optionen)',
+  },
+  optionsSchema: [
+    { key: 'strokeColor', label: 'Farbe', type: 'color' },
+    { key: 'startAngle', label: 'Bogen-Start (°)', type: 'number', min: 0, max: 360 },
+    { key: 'endAngle', label: 'Bogen-Ende (°)', type: 'number', min: 0, max: 360 },
+  ],
+  handlers: {
+    down(e, ctx) {
+      const c = ctx as FullToolContext;
+      if (ellipsePhase === 0) {
+        ellipseCenter = e.world;
+        ellipsePhase = 1;
+        ctx.setStatus('Ellipse: Zentrum gesetzt – RadiusX klicken (Richtung = Rotation)');
+      } else if (ellipsePhase === 1) {
+        if (!ellipseCenter) { ellipsePhase = 0; return; }
+        const dx = e.world.x - ellipseCenter.x;
+        const dy = e.world.y - ellipseCenter.y;
+        ellipseRadiusX = Math.hypot(dx, dy);
+        ellipseRotationDeg = ((Math.atan2(dy, dx) * 180) / Math.PI + 360) % 360;
+        ellipsePhase = 2;
+        ctx.setStatus('Ellipse: RadiusX gesetzt – RadiusY klicken');
+      } else {
+        // Phase 2: Commit
+        if (!ellipseCenter || !c.doc) { ellipsePhase = 0; ellipseCenter = null; return; }
+        const dx = e.world.x - ellipseCenter.x;
+        const dy = e.world.y - ellipseCenter.y;
+        const ry = Math.hypot(dx, dy);
+        // Rotation: Winkel des Klick2-Vektors gegenüber der +x-Achse
+        const startAngle = (ctx.options.startAngle as number | undefined) ?? 0;
+        const endAngle = (ctx.options.endAngle as number | undefined) ?? 360;
+        const el = buildEllipse(
+          ellipseCenter.x, ellipseCenter.y,
+          ellipseRadiusX, ry,
+          ellipseRotationDeg,
+          c, startAngle, endAngle,
+        );
+        c.doc.transact(() => c.doc!.addElement(el));
+        ellipsePhase = 0;
+        ellipseCenter = null;
+        ctx.setPreview?.(null);
+        ctx.setStatus(`Ellipse erstellt (${el.id})`);
+      }
+    },
+    move(e, ctx) {
+      const c = ctx as FullToolContext;
+      if (ellipsePhase === 1 && ellipseCenter) {
+        // RadiusX-Linie als Preview
+        const r = Math.hypot(e.world.x - ellipseCenter.x, e.world.y - ellipseCenter.y);
+        const rotDeg = ((Math.atan2(e.world.y - ellipseCenter.y, e.world.x - ellipseCenter.x) * 180) / Math.PI + 360) % 360;
+        const startAngle = (ctx.options.startAngle as number | undefined) ?? 0;
+        const endAngle = (ctx.options.endAngle as number | undefined) ?? 360;
+        ctx.setPreview?.(buildEllipse(ellipseCenter.x, ellipseCenter.y, r, r, rotDeg, c, startAngle, endAngle));
+      } else if (ellipsePhase === 2 && ellipseCenter) {
+        const ry = Math.hypot(e.world.x - ellipseCenter.x, e.world.y - ellipseCenter.y);
+        const rotDeg = ellipseRotationDeg;
+        const startAngle = (ctx.options.startAngle as number | undefined) ?? 0;
+        const endAngle = (ctx.options.endAngle as number | undefined) ?? 360;
+        ctx.setPreview?.(buildEllipse(ellipseCenter.x, ellipseCenter.y, ellipseRadiusX, ry, rotDeg, c, startAngle, endAngle));
+      }
+    },
+    cancel(ctx) {
+      ellipsePhase = 0;
+      ellipseCenter = null;
+      ctx.setPreview?.(null);
+      ctx.setStatus('Ellipse abgebrochen');
+    },
+  },
+};
+
+// ─────────────────────────────────────────────────────────────
+// Task D2: Spline (CV-basiert) — Kontrollpunkt-Klick-Sequenz,
+// ENTER committet ab 3 CVs. Catmull-Rom-Interpolation (Kurve läuft
+// DURCH alle CVs, schwingt an Ecken = echte Glättung).
+// ─────────────────────────────────────────────────────────────
+
+let splinePoints: Pt[] = [];
+
+/**
+ * Catmull-Rom-Spline-Interpolation: Für n CVs werden n-1 Segmente
+ * mit je SEG Samples erzeugt. Tangenten aus Nachbarn (Endpunkte
+ * geklemmt). Ergibt eine glatte Kurve durch alle CVs.
+ */
+function catmullRom(cvs: Pt[], seg = 16): Pt[] {
+  if (cvs.length < 2) return [...cvs];
+  const out: Pt[] = [];
+  const n = cvs.length;
+  for (let i = 0; i < n - 1; i++) {
+    const p0 = cvs[Math.max(0, i - 1)];
+    const p1 = cvs[i];
+    const p2 = cvs[i + 1];
+    const p3 = cvs[Math.min(n - 1, i + 2)];
+    for (let s = (i === 0 ? 0 : 1); s <= seg; s++) {
+      const t = s / seg;
+      const t2 = t * t;
+      const t3 = t2 * t;
+      const x = 0.5 * ((2 * p1.x) + (-p0.x + p2.x) * t + (2 * p0.x - 5 * p1.x + 4 * p2.x - p3.x) * t2 + (-p0.x + 3 * p1.x - 3 * p2.x + p3.x) * t3);
+      const y = 0.5 * ((2 * p1.y) + (-p0.y + p2.y) * t + (2 * p0.y - 5 * p1.y + 4 * p2.y - p3.y) * t2 + (-p0.y + 3 * p1.y - 3 * p2.y + p3.y) * t3);
+      out.push({ x, y });
+    }
+  }
+  return out;
+}
+
+function buildSpline(cvs: Pt[], ctx: FullToolContext): CADElement {
+  const stroke = (ctx.options.strokeColor as string | undefined) ?? '#e0e0f0';
+  const layerId = (ctx.options.layerId as string | undefined) ?? 'layer-0';
+  const pts = catmullRom(cvs);
+  const xs = pts.map((p) => p.x), ys = pts.map((p) => p.y);
+  const minX = Math.min(...xs), minY = Math.min(...ys);
+  const maxX = Math.max(...xs), maxY = Math.max(...ys);
+  return {
+    id: uid('spline'),
+    type: 'polyline',
+    layerId,
+    x: minX + (maxX - minX) / 2,
+    y: minY + (maxY - minY) / 2,
+    width: maxX - minX,
+    height: maxY - minY,
+    properties: {
+      points: pts,
+      controlPoints: [...cvs],
+      stroke,
+      strokeWidth: 1,
+    },
+  } as unknown as CADElement;
+}
+
+export const splineTool: ToolExtensionV2 = {
+  manifest: {
+    id: 'spline',
+    label: 'Spline',
+    icon: '\u2248',
+    ribbonTab: 'canvas',
+    tags: ['basic'],
+    description: 'Spline zeichnen: Kontrollpunkte klicken, ENTER beendet',
+  },
+  optionsSchema: [{ key: 'strokeColor', label: 'Farbe', type: 'color' }],
+  handlers: {
+    down(e, ctx) {
+      splinePoints.push(e.world);
+      ctx.setStatus(`Spline: ${splinePoints.length} Kontrollpunkte – ENTER beendet`);
+    },
+    move(e, ctx) {
+      const c = ctx as FullToolContext;
+      if (splinePoints.length === 0) return;
+      const pts = [...splinePoints, e.world];
+      ctx.setPreview?.(buildSpline(pts, c));
+    },
+    up() { /* commit nur via ENTER */ },
+    key(e, ctx) {
+      if (e.key !== 'Enter' && e.key !== 'ENTER') return false;
+      const c = ctx as FullToolContext;
+      if (splinePoints.length < 3) {
+        ctx.setStatus(`Spline benötigt mindestens 3 Kontrollpunkte (aktuell ${splinePoints.length})`);
+        return true;
+      }
+      if (!c.doc) return false;
+      const el = buildSpline(splinePoints, c);
+      c.doc.transact(() => c.doc!.addElement(el));
+      const count = splinePoints.length;
+      splinePoints = [];
+      ctx.setPreview?.(null);
+      ctx.setStatus(`Spline erstellt (${count} CVs, ${el.id})`);
+      return true;
+    },
+    cancel(ctx) {
+      splinePoints = [];
+      ctx.setPreview?.(null);
+      ctx.setStatus('Spline abgebrochen');
+    },
+  },
+};
+
+// ─────────────────────────────────────────────────────────────
+// Task D3: Point/XLine/Ray — Konstruktions-Elemente auf defpoints.
+// ─────────────────────────────────────────────────────────────
+
+/** Auto-Anlegen des defpoints-Layers (Task D3) falls fehlt. */
+function ensureDefpointsLayer(ctx: FullToolContext): void {
+  const doc = ctx.doc as unknown as {
+    getLayer(id: string): unknown;
+    addLayer(l: unknown): void;
+  } | undefined;
+  if (!doc || doc.getLayer('defpoints')) return;
+  doc.addLayer({
+    id: 'defpoints',
+    name: 'defpoints',
+    visible: true,
+    locked: false,
+    color: '#8a8f98',
+    lineType: 'dotted',
+    transparency: 0.5,
+    sortOrder: 999,
+    parentId: null,
+  });
+}
+
+/** Konstruktions-Element-Basis-Props (construction-Tags, Task D3). */
+function constructionProps(): Record<string, unknown> {
+  return { stroke: '#8a8f98', strokeWidth: 1, construction: true };
+}
+
+export const pointTool: ToolExtensionV2 = {
+  manifest: {
+    id: 'point',
+    label: 'Punkt',
+    icon: '\u2022',
+    ribbonTab: 'canvas',
+    tags: ['basic'],
+    description: 'Konstruktionspunkt platzieren (defpoints-Layer)',
+  },
+  optionsSchema: [],
+  handlers: {
+    down(e, ctx) {
+      const c = ctx as FullToolContext;
+      if (!c.doc) return;
+      ensureDefpointsLayer(c);
+      const r = 1.5;
+      const el: CADElement = {
+        id: uid('point'),
+        type: 'circle',
+        layerId: 'defpoints',
+        x: e.world.x,
+        y: e.world.y,
+        width: r * 2,
+        height: r * 2,
+        properties: { ...constructionProps(), radius: r, point: true },
+      } as unknown as CADElement;
+      c.doc.transact(() => c.doc!.addElement(el));
+      ctx.setStatus(`Punkt platziert (${el.id})`);
+    },
+  },
+};
+
+/** XLine: sehr lange Linie in BEIDE Richtungen um den Basispunkt. */
+let xlineBase: Pt | null = null;
+
+export const xlineTool: ToolExtensionV2 = {
+  manifest: {
+    id: 'xline',
+    label: 'Konstruktionslinie',
+    icon: '\u2194',
+    ribbonTab: 'canvas',
+    tags: ['basic'],
+    description: 'Unendliche Konstruktionslinie: Basispunkt + Richtung klicken',
+  },
+  optionsSchema: [],
+  handlers: {
+    down(e, ctx) {
+      const c = ctx as FullToolContext;
+      if (!c.doc) return;
+      if (!xlineBase) {
+        xlineBase = e.world;
+        ctx.setStatus('Konstruktionslinie: Basis gesetzt – Richtung klicken');
+        return;
+      }
+      ensureDefpointsLayer(c);
+      const dx = e.world.x - xlineBase.x;
+      const dy = e.world.y - xlineBase.y;
+      const len = Math.hypot(dx, dy);
+      if (len < 0.001) { xlineBase = null; return; }
+      const ux = dx / len, uy = dy / len;
+      const L = 100000;
+      const el: CADElement = {
+        id: uid('xline'),
+        type: 'line',
+        layerId: 'defpoints',
+        x: xlineBase.x,
+        y: xlineBase.y,
+        width: 0,
+        height: 0,
+        properties: {
+          ...constructionProps(),
+          x1: xlineBase.x - ux * L,
+          y1: xlineBase.y - uy * L,
+          x2: xlineBase.x + ux * L,
+          y2: xlineBase.y + uy * L,
+        },
+      } as unknown as CADElement;
+      c.doc.transact(() => c.doc!.addElement(el));
+      xlineBase = null;
+      ctx.setPreview?.(null);
+      ctx.setStatus(`Konstruktionslinie erstellt (${el.id})`);
+    },
+    move(e, ctx) {
+      const c = ctx as FullToolContext;
+      if (!xlineBase) return;
+      const dx = e.world.x - xlineBase.x;
+      const dy = e.world.y - xlineBase.y;
+      const len = Math.hypot(dx, dy);
+      if (len < 0.001) return;
+      const ux = dx / len, uy = dy / len;
+      const L = 100000;
+      ctx.setPreview?.({
+        id: '__preview_xline__',
+        type: 'line',
+        layerId: 'defpoints',
+        x: xlineBase.x,
+        y: xlineBase.y,
+        width: 0,
+        height: 0,
+        properties: {
+          ...constructionProps(),
+          x1: xlineBase.x - ux * L,
+          y1: xlineBase.y - uy * L,
+          x2: xlineBase.x + ux * L,
+          y2: xlineBase.y + uy * L,
+        },
+      } as unknown as CADElement);
+    },
+    cancel(ctx) {
+      xlineBase = null;
+      ctx.setPreview?.(null);
+      ctx.setStatus('Konstruktionslinie abgebrochen');
+    },
+  },
+};
+
+/** Ray: Linie ab Basispunkt NUR in Klickrichtung. */
+let rayBase: Pt | null = null;
+
+export const rayTool: ToolExtensionV2 = {
+  manifest: {
+    id: 'ray',
+    label: 'Strahl',
+    icon: '\u2192',
+    ribbonTab: 'canvas',
+    tags: ['basic'],
+    description: 'Strahl ab Basispunkt in Klickrichtung',
+  },
+  optionsSchema: [],
+  handlers: {
+    down(e, ctx) {
+      const c = ctx as FullToolContext;
+      if (!c.doc) return;
+      if (!rayBase) {
+        rayBase = e.world;
+        ctx.setStatus('Strahl: Basis gesetzt – Richtung klicken');
+        return;
+      }
+      ensureDefpointsLayer(c);
+      const dx = e.world.x - rayBase.x;
+      const dy = e.world.y - rayBase.y;
+      const len = Math.hypot(dx, dy);
+      if (len < 0.001) { rayBase = null; return; }
+      const ux = dx / len, uy = dy / len;
+      const L = 100000;
+      const el: CADElement = {
+        id: uid('ray'),
+        type: 'line',
+        layerId: 'defpoints',
+        x: rayBase.x,
+        y: rayBase.y,
+        width: 0,
+        height: 0,
+        properties: {
+          ...constructionProps(),
+          x1: rayBase.x,
+          y1: rayBase.y,
+          x2: rayBase.x + ux * L,
+          y2: rayBase.y + uy * L,
+        },
+      } as unknown as CADElement;
+      c.doc.transact(() => c.doc!.addElement(el));
+      rayBase = null;
+      ctx.setPreview?.(null);
+      ctx.setStatus(`Strahl erstellt (${el.id})`);
+    },
+    move(e, ctx) {
+      const c = ctx as FullToolContext;
+      if (!rayBase) return;
+      const dx = e.world.x - rayBase.x;
+      const dy = e.world.y - rayBase.y;
+      const len = Math.hypot(dx, dy);
+      if (len < 0.001) return;
+      const ux = dx / len, uy = dy / len;
+      const L = 100000;
+      ctx.setPreview?.({
+        id: '__preview_ray__',
+        type: 'line',
+        layerId: 'defpoints',
+        x: rayBase.x,
+        y: rayBase.y,
+        width: 0,
+        height: 0,
+        properties: {
+          ...constructionProps(),
+          x1: rayBase.x,
+          y1: rayBase.y,
+          x2: rayBase.x + ux * L,
+          y2: rayBase.y + uy * L,
+        },
+      } as unknown as CADElement);
+    },
+    cancel(ctx) {
+      rayBase = null;
+      ctx.setPreview?.(null);
+      ctx.setStatus('Strahl abgebrochen');
+    },
+  },
+};
+
+export const coreDrawingPlugin: PluginV2 = {
+  manifest: {
+    id: 'core-drawing',
+    name: 'Zeichnen (Kern)',
+    version: '1.5.0',
+    author: 'web-cad team',
+    description: 'Zeichenwerkzeuge V2: Linie, Rechteck, Kreis, Bogen, Polylinie, Polygon, RevCloud.',
+    category: 'tools',
+    enabledByDefault: true,
+  },
+  tools: [lineTool, rectTool, circleTool, arcTool, polylineTool, polygonTool, revcloudTool, ellipseTool, splineTool, pointTool, xlineTool, rayTool],
+};

frontend/src/plugins/builtin/core-measure/index.ts

@@ -0,0 +1,125 @@
+/**
+ * core-measure – Built-in V2-Plugin (Task A4.5).
+ *
+ * measure: 2 Klicks → Distanz+Winkel-Anzeige im Status. KEIN Element-Commit
+ * (Legacy-Verhalten getreu — Messung ist Information, keine Zeichnung).
+ * Distanzformatierung via bestehendem formatDistance(unit, scaleFactor).
+ */
+import type { PluginV2, ToolExtensionV2, FullToolContext } from '../../types';
+import { formatDistance, formatArea } from '../../../utils/format';
+import { polygonArea } from '../../../tools/modification/geometry';
+
+type MeasurePhase = 0 | 1; // 0=wartet auf Start, 1=wartet auf Ende
+let measureStart: import('../../../tools/modification/geometry').Pt | null = null;
+
+export const measureTool: ToolExtensionV2 = {
+  manifest: {
+    id: 'measure',
+    label: 'Messen',
+    icon: '\u2194',
+    ribbonTab: 'view',
+    tags: ['basic'],
+    description: 'Distanz und Winkel zwischen zwei Punkten messen',
+  },
+  optionsSchema: [],
+  handlers: {
+    down(e, ctx) {
+      const c = ctx as FullToolContext;
+      if (!measureStart) {
+        measureStart = e.world;
+        ctx.setStatus('Messung: Endpunkt klicken');
+        return;
+      }
+      // Zweiter Klick → anzeigen (Legacy-Ausgabeformat)
+      const rawDist = Math.hypot(e.world.x - measureStart.x, e.world.y - measureStart.y);
+      const angle = (Math.atan2(e.world.y - measureStart.y, e.world.x - measureStart.x) * 180) / Math.PI;
+      const unit = (c.options.unit as string | undefined) ?? 'mm';
+      const scale = (c.options.scaleFactor as number | undefined) ?? 1;
+      const distStr = formatDistance(rawDist, unit as never, scale);
+      ctx.setStatus(`distance: ${distStr}  angle: ${angle.toFixed(1)}\u00b0`);
+      measureStart = null;
+    },
+    cancel(ctx) {
+      measureStart = null;
+      ctx.setStatus('Messung abgebrochen');
+    },
+  },
+};
+
+/** V2-Plugin: Messwerkzeuge. */
+// ─────────────────────────────────────────────────────────────
+// Task H5: measure-area — Polygon-Fläche messen (Status-only).
+// Klick: Punkt hinzufügen; ENTER: committet Fläche ab 3 Punkten;
+// ESC/Rechtsklick: Abbruch. Kein Element-Commit (wie measure).
+// ─────────────────────────────────────────────────────────────
+let areaPts: Array<{ x: number; y: number }> = [];
+
+export const measureAreaTool: ToolExtensionV2 = {
+  manifest: {
+    id: 'measure-area',
+    label: 'Fläche messen',
+    icon: '\u25a9',
+    ribbonTab: 'canvas',
+    tags: ['basic'],
+    description: 'Polygon-Fläche messen: Punkte klicken, ENTER schließt ab',
+  },
+  optionsSchema: [
+    { key: 'unit', label: 'Einheit', type: 'select', options: [
+      { value: 'mm', label: 'mm' }, { value: 'cm', label: 'cm' }, { value: 'm', label: 'm' },
+    ] },
+    { key: 'scaleFactor', label: 'Maßstab (Welt→mm)', type: 'number' },
+  ],
+  handlers: {
+    down(e, ctx) {
+      areaPts.push({ x: e.world.x, y: e.world.y });
+      if (areaPts.length === 1) {
+        ctx.setStatus(`Flächenmessung gestartet (1 Punkt) — weitere Punkte klicken, ENTER schließt ab`);
+      } else if (areaPts.length >= 3) {
+        const unit = (ctx.options.unit as string | undefined) ?? 'mm';
+        const scale = (ctx.options.scaleFactor as number | undefined) ?? 1;
+        ctx.setStatus(`Fläche: ${formatArea(polygonArea(areaPts), unit as never, scale)} — weiter klicken oder ENTER`);
+      } else {
+        ctx.setStatus(`${areaPts.length} Punkte — mindestens 3 benötigt, weitere Punkte klicken`);
+      }
+    },
+    move(e, ctx) {
+      if (areaPts.length < 2) return;
+      const probe = [...areaPts, { x: e.world.x, y: e.world.y }];
+      if (probe.length < 3) return;
+      const unit = (ctx.options.unit as string | undefined) ?? 'mm';
+      const scale = (ctx.options.scaleFactor as number | undefined) ?? 1;
+      ctx.setStatus(`Fläche: ${formatArea(polygonArea(probe), unit as never, scale)}`);
+    },
+    key(k, ctx) {
+      if (k.key === 'Enter' || k.key === 'ENTER') {
+        if (areaPts.length >= 3) {
+          const unit = (ctx.options.unit as string | undefined) ?? 'mm';
+          const scale = (ctx.options.scaleFactor as number | undefined) ?? 1;
+          ctx.setStatus(`Flächenmessung: ${formatArea(polygonArea(areaPts), unit as never, scale)} (${areaPts.length} Punkte)`);
+          areaPts = [];
+        } else {
+          ctx.setStatus(`Flächenmessung benötigt mindestens 3 Punkte (aktuell ${areaPts.length})`);
+        }
+        return true; // ENTER konsumiert
+      }
+      return false;
+    },
+    cancel(ctx) {
+      areaPts = [];
+      ctx.setStatus('Flächenmessung abgebrochen');
+    },
+  },
+};
+
+export const coreMeasurePlugin: PluginV2 = {
+  manifest: {
+    id: 'core-measure',
+    name: 'Messen (Kern)',
+    version: '1.0.0',
+    author: 'web-cad team',
+    description: 'Abstandswinkel-Messung ohne Element-Erzeugung.',
+    category: 'tools',
+    enabledByDefault: true,
+  },
+  tools: [measureTool, measureAreaTool],
+};

frontend/src/plugins/builtin/event-tools/index.ts

@@ -0,0 +1,435 @@
+/**
+ * event-tools – Built-in V2-Plugin (Tasks A4.9 + E1).
+ *
+ * Fachwerkzeuge für Veranstaltungsplanung: chair (Einzelnklick),
+ * seating-row + seating-block (Drag-Interaktion mit Live-Preview
+ * und Options-Schema), table + stage (Einzelnklick).
+ *
+ * Jede Platzierung = doc.transact → 1 Undo-Schritt (Multi-Element-Sets
+ * wie seating-block erscheinen/verschwinden gemeinsam).
+ *
+ * SeatingService ist durch BUG-1-Fix deterministisch (rowIds unique).
+ */
+import type { PluginV2, ToolExtensionV2, FullToolContext } from '../../types';
+import type { CADElement } from '../../../types/cad.types';
+import type { Pt } from '../../../tools/modification/geometry';
+import { SeatingService } from '../../../services/seatingService';
+
+const seating = new SeatingService();
+
+// ─── Drag-Sitzungs-State für row/block ─────────────────────
+let dragStart: Pt | null = null;
+
+function optsOf(ctx: FullToolContext): { layerId: string } {
+  return {
+    layerId: (ctx.options.layerId as string | undefined) ?? 'layer-0',
+  };
+}
+
+/** Erzeugt ein Einzelklick-Platzierer-Werkzeug über einen placer. */
+function makePlaceTool(
+  id: string,
+  label: string,
+  icon: string,
+  placer: (x: number, y: number, layerId: string) => CADElement | CADElement[],
+  statusNoun: string,
+): ToolExtensionV2 {
+  return {
+    manifest: {
+      id,
+      label,
+      icon,
+      ribbonTab: 'insert',
+      tags: ['basic'],
+      description: `${statusNoun} per Klick platzieren`,
+    },
+    optionsSchema: [],
+    handlers: {
+      down(e, ctx) {
+        const c = ctx as FullToolContext;
+        if (!c.doc) return;
+        const { layerId } = optsOf(ctx);
+        const placed = placer(e.world.x, e.world.y, layerId);
+        const els = Array.isArray(placed) ? placed : [placed];
+        c.doc.transact(() => {
+          for (const el of els) c.doc!.addElement(el);
+        });
+        ctx.setStatus(`${statusNoun} platziert (${els.length} Element${els.length === 1 ? '' : 'e'})`);
+      },
+    },
+  };
+}
+
+/**
+ * seating-row (Task E1): Klick1 = Start, Drag = Länge/Vorschau,
+ * up = Commit. Anzahl Stühle wird aus Distanz berechnet (spacing aus Options).
+ */
+export const seatingRowToolDrag: ToolExtensionV2 = {
+  manifest: {
+    id: 'seating-row',
+    label: 'Stuhldreihe',
+    icon: '\u2500\u2570\u2500',
+    ribbonTab: 'insert',
+    tags: ['basic'],
+    description: 'Reihe: Start klicken, Ende ziehen. Stuhlzahl aus Länge.',
+  },
+  optionsSchema: [
+    { key: 'spacing', label: 'Abstand (cm)', type: 'number', min: 20, max: 200 },
+  ],
+  handlers: {
+    down(e, ctx) {
+      dragStart = e.world;
+      ctx.setStatus('Reihe: Endpunkt ziehen');
+    },
+    move(e, ctx) {
+      if (!dragStart) return;
+      const c = ctx as FullToolContext;
+      const { layerId } = optsOf(c);
+      const spacing = (c.options.spacing as number | undefined) ?? 50;
+      const length = Math.hypot(e.world.x - dragStart.x, e.world.y - dragStart.y);
+      const count = Math.max(2, Math.floor(length / spacing));
+      const preview = seating.createSeatingRow(dragStart.x, dragStart.y, layerId, { count, spacing });
+      c.setPreview?.(preview[0] ?? null); // Legacy-Vorschau zeigt ersten Stuhl als Referenz
+      ctx.setStatus(`Reihe: ${count} Stühle (${length.toFixed(0)}mm)`);
+    },
+    up(e, ctx) {
+      const c = ctx as FullToolContext;
+      if (!dragStart || !c.doc) { dragStart = null; return; }
+      const { layerId } = optsOf(c);
+      const spacing = (c.options.spacing as number | undefined) ?? 50;
+      const length = Math.hypot(e.world.x - dragStart.x, e.world.y - dragStart.y);
+      const count = Math.max(2, Math.floor(length / spacing));
+      const els = seating.createSeatingRow(dragStart.x, dragStart.y, layerId, { count, spacing });
+      c.doc.transact(() => {
+        for (const el of els) c.doc!.addElement(el);
+      });
+      ctx.setStatus(`Reihe: ${count} Stühle platziert`);
+      dragStart = null;
+      c.setPreview?.(null);
+    },
+    cancel(ctx) {
+      dragStart = null;
+      ctx.setPreview?.(null);
+      ctx.setStatus('Reihe abgebrochen');
+    },
+  },
+};
+
+/**
+ * seating-block (Task E1): Klick1 = Start-Ecke, Drag = Block-Dimension,
+ * up = Commit. rows/cols aus Distanz + spacing berechnet.
+ */
+export const seatingBlockToolDrag: ToolExtensionV2 = {
+  manifest: {
+    id: 'seating-block',
+    label: 'Stuhlblock',
+    icon: '\u2565',
+    ribbonTab: 'insert',
+    tags: ['basic'],
+    description: 'Block: Start-Ecke klicken, Gegenecke ziehen.',
+  },
+  optionsSchema: [
+    { key: 'colSpacing', label: 'Sitzabstand X (cm)', type: 'number', min: 30, max: 200 },
+    { key: 'rowSpacing', label: 'Reihenabstand Y (cm)', type: 'number', min: 30, max: 200 },
+  ],
+  handlers: {
+    down(e, ctx) {
+      dragStart = e.world;
+      ctx.setStatus('Block: Gegenecke ziehen');
+    },
+    move(e, ctx) {
+      if (!dragStart) return;
+      const c = ctx as FullToolContext;
+      const { layerId } = optsOf(c);
+      const colSpacing = (c.options.colSpacing as number | undefined) ?? 50;
+      const rowSpacing = (c.options.rowSpacing as number | undefined) ?? 50;
+      const w = Math.abs(e.world.x - dragStart.x);
+      const h = Math.abs(e.world.y - dragStart.y);
+      const cols = Math.max(2, Math.floor(w / colSpacing));
+      const rows = Math.max(2, Math.floor(h / rowSpacing));
+      ctx.setStatus(`Block: ${rows} Reihen × ${cols} Stühle = ${rows * cols} Sitzplätze`);
+    },
+    up(e, ctx) {
+      const c = ctx as FullToolContext;
+      if (!dragStart || !c.doc) { dragStart = null; return; }
+      const { layerId } = optsOf(c);
+      const colSpacing = (c.options.colSpacing as number | undefined) ?? 50;
+      const rowSpacing = (c.options.rowSpacing as number | undefined) ?? 50;
+      const w = Math.abs(e.world.x - dragStart.x);
+      const h = Math.abs(e.world.y - dragStart.y);
+      const cols = Math.max(2, Math.floor(w / colSpacing));
+      const rows = Math.max(2, Math.floor(h / rowSpacing));
+      const centerX = (dragStart.x + e.world.x) / 2;
+      const centerY = (dragStart.y + e.world.y) / 2;
+      const els = seating.createSeatingBlock(centerX, centerY, layerId, { rows, cols, colSpacing, rowSpacing });
+      c.doc.transact(() => {
+        for (const el of els) c.doc!.addElement(el);
+      });
+      ctx.setStatus(`Block: ${rows}×${cols} = ${els.length} Stühle platziert`);
+      dragStart = null;
+      c.setPreview?.(null);
+    },
+    cancel(ctx) {
+      dragStart = null;
+      ctx.setPreview?.(null);
+      ctx.setStatus('Block abgebrochen');
+    },
+  },
+};
+
+export const chairTool = makePlaceTool('chair', 'Stuhl', '\u2570',
+  (x, y, layerId) => seating.createChair(x, y, layerId), 'Stuhl');
+
+export const tableTool = makePlaceTool('table', 'Tisch', '\u25cb',
+  (x, y, layerId) => seating.createTable(x, y, layerId), 'Tisch');
+
+export const stageTool = makePlaceTool('stage', 'Bühne', '\u25ad',
+  (x, y, layerId) => seating.createStage(x, y, layerId), 'Bühne');
+
+// ─────────────────────────────────────────────────────────────
+// Task E4: Vorlagenkatalog — vorkonfigurierte Event-Bestuhlungs-
+// Sets als Klick-Platzierer mit Standard-Abmessungen.
+// ─────────────────────────────────────────────────────────────
+export const kinoTemplateTool = makePlaceTool('tpl-kino', 'Kino-Reihen', '\u2500\u2500',
+  (x, y, layerId) => {
+    const rows: CADElement[] = [];
+    for (let r = 0; r < 5; r++) {
+      rows.push(...seating.createSeatingRow(x, y + r * 120, layerId, { count: 15, spacing: 55 }));
+    }
+    return rows;
+  }, 'Kino-Bestuhlung (5×15)');
+
+export const banquetTemplateTool = makePlaceTool('tpl-bankett', 'Bankett-Rundtisch', '\u25cb',
+  (x, y, layerId) => {
+    const els: CADElement[] = [];
+    els.push(seating.createTable(x, y, layerId, { width: 180, height: 180 }));
+    for (let i = 0; i < 8; i++) {
+      const angle = (2 * Math.PI * i) / 8;
+      els.push(seating.createChair(x + 140 * Math.cos(angle), y + 140 * Math.sin(angle), layerId));
+    }
+    return els;
+  }, 'Bankett-Rundtisch (8 Stühle)');
+
+export const standingTableTemplateTool = makePlaceTool('tpl-standing', 'Stehtisch', '\u25d1',
+  (x, y, layerId) => {
+    const els: CADElement[] = [];
+    els.push(seating.createTable(x, y, layerId, { width: 80, height: 80 }));
+    for (let i = 0; i < 5; i++) {
+      const angle = (2 * Math.PI * i) / 5;
+      els.push(seating.createChair(x + 70 * Math.cos(angle), y + 70 * Math.sin(angle), layerId));
+    }
+    return els;
+  }, 'Stehtisch (5 Stühle)');
+
+export const podiumTemplateTool = makePlaceTool('tpl-podium', 'Podest', '\u25ac',
+  (x, y, layerId) => seating.createStage(x, y, layerId, { width: 300, height: 200 }), 'Podest');
+
+// ─────────────────────────────────────────────────────────────
+// Arc-Row (Task E2): Reihen entlang Kreisbogen um Bühnenpunkt.
+// Klick 1: Zentrum (Bühne). Drag: Radius + Startwinkel.
+// Klick 2: Endwinkel → Commit.
+// Phasen: 0=Zentrum setzen, 1=Radius+Start, 2=Endwinkel → commit
+// ─────────────────────────────────────────────────────────────
+let arcCenter: Pt | null = null;
+let arcStartPt: Pt | null = null;
+let arcPhase = 0;
+
+export const arcRowTool: ToolExtensionV2 = {
+  manifest: {
+    id: 'arc-row',
+    label: 'Arc-Row',
+    icon: '\u2312',
+    ribbonTab: 'insert',
+    tags: ['basic'],
+    description: 'Bogenreihe: Zentrum, Startpunkt, Endpunkt klicken',
+  },
+  optionsSchema: [
+    { key: 'arcSpacing', label: 'Abstand (cm)', type: 'number', min: 20, max: 200 },
+  ],
+  handlers: {
+    down(e, ctx) {
+      const c = ctx as FullToolContext;
+      const { layerId } = optsOf(c);
+      const spacing = (c.options.arcSpacing as number | undefined) ?? 50;
+      if (arcPhase === 0) {
+        arcCenter = e.world;
+        arcPhase = 1;
+        ctx.setStatus('Arc-Row: Radius ziehen (Startpunkt)');
+      } else if (arcPhase === 1 && arcCenter) {
+        arcStartPt = e.world;
+        arcPhase = 2;
+        ctx.setStatus('Arc-Row: Endwinkel klicken');
+      } else if (arcPhase === 2 && arcCenter && arcStartPt && c.doc) {
+        const els = seating.createArcRow(arcCenter.x, arcCenter.y, Math.hypot(arcStartPt.x - arcCenter.x, arcStartPt.y - arcCenter.y),
+          (Math.atan2(arcStartPt.y - arcCenter.y, arcStartPt.x - arcCenter.x) * 180) / Math.PI,
+          (Math.atan2(e.world.y - arcCenter.y, e.world.x - arcCenter.x) * 180) / Math.PI,
+          layerId, spacing);
+        c.doc.transact(() => {
+          for (const el of els) c.doc!.addElement(el);
+        });
+        ctx.setStatus(`Arc-Row: ${els.length} Stühle platziert`);
+        arcPhase = 0; arcCenter = null; arcStartPt = null;
+      }
+    },
+    cancel(ctx) {
+      arcPhase = 0; arcCenter = null; arcStartPt = null;
+      ctx.setPreview?.(null);
+      ctx.setStatus('Arc-Row abgebrochen');
+    },
+  },
+};
+
+/** V2-Plugin: Event-Domain (Tasks A4.9 + E1). */
+// ─────────────────────────────────────────────────────────────
+// Task E7: Event-Elemente-Polish — curtain, spotlight, barrier
+// ─────────────────────────────────────────────────────────────
+
+/** Vorhang: wellige Polyline (Standardbreite 400) über der Bühne. */
+export const curtainTool: ToolExtensionV2 = {
+  manifest: {
+    id: 'curtain',
+    label: 'Vorhang',
+    icon: '╭',
+    ribbonTab: 'insert',
+    tags: ['basic'],
+    description: 'Vorhang entlang der Bühnen-Oberkante platzieren',
+  },
+  optionsSchema: [
+    { key: 'stageHeight', label: 'Höhe (cm)', type: 'number' },
+  ],
+  handlers: {
+    down(e, ctx) {
+      const c = ctx as FullToolContext;
+      if (!c.doc) return;
+      const { layerId } = optsOf(ctx);
+      const stageHeight = (ctx.options.stageHeight as number | undefined) ?? 120;
+      const width = 400;
+      // Wellenform: 24 Punkte, Sinus gedämpft an den Enden
+      const pts: Pt[] = [];
+      const SEG = 24;
+      for (let i = 0; i <= SEG; i++) {
+        const t = i / SEG;
+        const x = e.world.x - width / 2 + width * t;
+        const y = e.world.y + Math.sin(t * Math.PI) * (stageHeight / 4);
+        pts.push({ x, y });
+      }
+      const el: CADElement = {
+        id: `curtain-${Date.now()}-${Math.random().toString(36).slice(2, 7)}`,
+        type: 'curtain',
+        layerId,
+        x: e.world.x,
+        y: e.world.y,
+        width,
+        height: stageHeight,
+        properties: { points: pts, stageHeight, stroke: '#7a4a8f', strokeWidth: 2 },
+      };
+      c.doc.transact(() => { c.doc!.addElement(el); });
+      ctx.setStatus(`Vorhang platziert (${width} breit, ${stageHeight} cm hoch)`);
+    },
+  },
+};
+
+/** Scheinwerfer: Lichtkegel in angle-Richtung mit Farbe. */
+export const spotlightTool: ToolExtensionV2 = {
+  manifest: {
+    id: 'spotlight',
+    label: 'Scheinwerfer',
+    icon: '▶',
+    ribbonTab: 'insert',
+    tags: ['basic'],
+    description: 'Scheinwerfer-Kegel platzieren (Winkel + Farbe aus Optionen)',
+  },
+  optionsSchema: [
+    { key: 'angle', label: 'Winkel (°)', type: 'number' },
+    { key: 'color', label: 'Lichtfarbe', type: 'color' },
+  ],
+  handlers: {
+    down(e, ctx) {
+      const c = ctx as FullToolContext;
+      if (!c.doc) return;
+      const { layerId } = optsOf(ctx);
+      const angle = (ctx.options.angle as number | undefined) ?? 0;
+      const color = (ctx.options.color as string | undefined) ?? '#ffcc00';
+      const length = 300;
+      const halfAngle = 20;
+      const rad = (angle * Math.PI) / 180;
+      const radHalf = (halfAngle * Math.PI) / 180;
+      const p1 = { x: e.world.x + length * Math.cos(rad - radHalf), y: e.world.y + length * Math.sin(rad - radHalf) };
+      const p2 = { x: e.world.x + length * Math.cos(rad + radHalf), y: e.world.y + length * Math.sin(rad + radHalf) };
+      const pts: Pt[] = [
+        { x: e.world.x, y: e.world.y },
+        p1,
+        p2,
+        { x: e.world.x, y: e.world.y },
+      ];
+      const el: CADElement = {
+        id: `spotlight-${Date.now()}-${Math.random().toString(36).slice(2, 7)}`,
+        type: 'spotlight',
+        layerId,
+        x: e.world.x,
+        y: e.world.y,
+        width: length,
+        height: length,
+        properties: { points: pts, angle, color },
+      };
+      c.doc.transact(() => { c.doc!.addElement(el); });
+      ctx.setStatus(`Scheinwerfer platziert (${angle}°, ${color})`);
+    },
+  },
+};
+
+/** Absperrung: Kette aus Kreis-Paaren entlang Standardlänge 200. */
+export const barrierTool: ToolExtensionV2 = {
+  manifest: {
+    id: 'barrier',
+    label: 'Absperrung',
+    icon: '⛴',
+    ribbonTab: 'insert',
+    tags: ['basic'],
+    description: 'Absperr-Kette (Kreis-Paare) platzieren',
+  },
+  optionsSchema: [
+    { key: 'length', label: 'Länge', type: 'number' },
+  ],
+  handlers: {
+    down(e, ctx) {
+      const c = ctx as FullToolContext;
+      if (!c.doc) return;
+      const { layerId } = optsOf(ctx);
+      const length = (ctx.options.length as number | undefined) ?? 200;
+      const circles: Array<{ x: number; y: number; r: number }> = [];
+      const pairs = 6;
+      for (let i = 0; i < pairs; i++) {
+        const t = (i + 0.5) / pairs;
+        const cx = e.world.x - length / 2 + length * t;
+        circles.push({ x: cx, y: e.world.y - 10, r: 8 });
+        circles.push({ x: cx, y: e.world.y + 10, r: 8 });
+      }
+      const el: CADElement = {
+        id: `barrier-${Date.now()}-${Math.random().toString(36).slice(2, 7)}`,
+        type: 'barrier',
+        layerId,
+        x: e.world.x,
+        y: e.world.y,
+        width: length,
+        height: 20,
+        properties: { circles, color: '#c0392b' },
+      };
+      c.doc.transact(() => { c.doc!.addElement(el); });
+      ctx.setStatus(`Absperrung platziert (${length} lang, ${pairs} Kettenglieder)`);
+    },
+  },
+};
+
+export const eventToolsV2Plugin: PluginV2 = {
+  manifest: {
+    id: 'event-tools',
+    name: 'Event-Bestuhlung',
+    version: '2.2.0',
+    author: 'web-cad team',
+    description: 'Stühle, Reihen (Drag), Blöcke (Drag), Tische, Bühne, Vorhang, Scheinwerfer, Absperrung (V2).',
+    category: 'elements',
+    enabledByDefault: true,
+  },
+  tools: [chairTool, seatingRowToolDrag, seatingBlockToolDrag, tableTool, stageTool, arcRowTool, kinoTemplateTool, banquetTemplateTool, standingTableTemplateTool, podiumTemplateTool, curtainTool, spotlightTool, barrierTool],
+};

frontend/src/plugins/builtin/library/catalogs/architecture.json

@@ -0,0 +1,587 @@
+{
+ "folderId": "cat-arch",
+ "label": "Architektur-Katalog",
+ "blocks": [
+  {
+   "id": "arch-1",
+   "name": "Tür 900",
+   "elements": [
+    {
+     "id": "a1a",
+     "type": "line",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 0,
+     "height": 0,
+     "properties": {
+      "x1": 0,
+      "y1": 0,
+      "x2": 900,
+      "y2": 0
+     }
+    },
+    {
+     "id": "a1b",
+     "type": "arc",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 1800,
+     "height": 1800,
+     "properties": {
+      "radius": 900,
+      "startAngle": 0,
+      "endAngle": 90
+     }
+    }
+   ]
+  },
+  {
+   "id": "arch-2",
+   "name": "Doppel-Tür 1800",
+   "elements": [
+    {
+     "id": "a2a",
+     "type": "line",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 0,
+     "height": 0,
+     "properties": {
+      "x1": -900,
+      "y1": 0,
+      "x2": -450,
+      "y2": 0
+     }
+    },
+    {
+     "id": "a2b",
+     "type": "arc",
+     "layerId": "layer-0",
+     "x": -900,
+     "y": 0,
+     "width": 900,
+     "height": 900,
+     "properties": {
+      "radius": 450,
+      "startAngle": 0,
+      "endAngle": 90
+     }
+    },
+    {
+     "id": "a2c",
+     "type": "line",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 0,
+     "height": 0,
+     "properties": {
+      "x1": 450,
+      "y1": 0,
+      "x2": 900,
+      "y2": 0
+     }
+    },
+    {
+     "id": "a2d",
+     "type": "arc",
+     "layerId": "layer-0",
+     "x": 900,
+     "y": 0,
+     "width": 900,
+     "height": 900,
+     "properties": {
+      "radius": 450,
+      "startAngle": 90,
+      "endAngle": 180
+     }
+    }
+   ]
+  },
+  {
+   "id": "arch-3",
+   "name": "Tür 1200",
+   "elements": [
+    {
+     "id": "a3a",
+     "type": "line",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 0,
+     "height": 0,
+     "properties": {
+      "x1": 0,
+      "y1": 0,
+      "x2": 1200,
+      "y2": 0
+     }
+    },
+    {
+     "id": "a3b",
+     "type": "arc",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 2400,
+     "height": 2400,
+     "properties": {
+      "radius": 1200,
+      "startAngle": 0,
+      "endAngle": 90
+     }
+    }
+   ]
+  },
+  {
+   "id": "arch-4",
+   "name": "Fenster 1200",
+   "elements": [
+    {
+     "id": "a4a",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": -30,
+     "width": 1200,
+     "height": 20,
+     "properties": {}
+    },
+    {
+     "id": "a4b",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 30,
+     "width": 1200,
+     "height": 20,
+     "properties": {}
+    }
+   ]
+  },
+  {
+   "id": "arch-5",
+   "name": "Fenster 2400",
+   "elements": [
+    {
+     "id": "a5a",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": -30,
+     "width": 2400,
+     "height": 20,
+     "properties": {}
+    },
+    {
+     "id": "a5b",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 30,
+     "width": 2400,
+     "height": 20,
+     "properties": {}
+    }
+   ]
+  },
+  {
+   "id": "arch-6",
+   "name": "Wandstück 2m",
+   "elements": [
+    {
+     "id": "a6a",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 2000,
+     "height": 240,
+     "properties": {
+      "fill": "#8a8f98"
+     }
+    }
+   ]
+  },
+  {
+   "id": "arch-7",
+   "name": "Wandstück vertikal 2m",
+   "elements": [
+    {
+     "id": "a7a",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 240,
+     "height": 2000,
+     "properties": {
+      "fill": "#8a8f98"
+     }
+    }
+   ]
+  },
+  {
+   "id": "arch-8",
+   "name": "Treppe (8 Stufen)",
+   "elements": [
+    {
+     "id": "a8s0",
+     "type": "line",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 0,
+     "height": 0,
+     "properties": {
+      "x1": -350,
+      "y1": 0,
+      "x2": -350,
+      "y2": 1200
+     }
+    },
+    {
+     "id": "a8s1",
+     "type": "line",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 0,
+     "height": 0,
+     "properties": {
+      "x1": -250,
+      "y1": 0,
+      "x2": -250,
+      "y2": 1200
+     }
+    },
+    {
+     "id": "a8s2",
+     "type": "line",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 0,
+     "height": 0,
+     "properties": {
+      "x1": -150,
+      "y1": 0,
+      "x2": -150,
+      "y2": 1200
+     }
+    },
+    {
+     "id": "a8s3",
+     "type": "line",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 0,
+     "height": 0,
+     "properties": {
+      "x1": -50,
+      "y1": 0,
+      "x2": -50,
+      "y2": 1200
+     }
+    },
+    {
+     "id": "a8s4",
+     "type": "line",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 0,
+     "height": 0,
+     "properties": {
+      "x1": 50,
+      "y1": 0,
+      "x2": 50,
+      "y2": 1200
+     }
+    },
+    {
+     "id": "a8s5",
+     "type": "line",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 0,
+     "height": 0,
+     "properties": {
+      "x1": 150,
+      "y1": 0,
+      "x2": 150,
+      "y2": 1200
+     }
+    },
+    {
+     "id": "a8s6",
+     "type": "line",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 0,
+     "height": 0,
+     "properties": {
+      "x1": 250,
+      "y1": 0,
+      "x2": 250,
+      "y2": 1200
+     }
+    },
+    {
+     "id": "a8s7",
+     "type": "line",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 0,
+     "height": 0,
+     "properties": {
+      "x1": 350,
+      "y1": 0,
+      "x2": 350,
+      "y2": 1200
+     }
+    },
+    {
+     "id": "a8la",
+     "type": "line",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 0,
+     "height": 0,
+     "properties": {
+      "x1": -450,
+      "y1": 0,
+      "x2": -450,
+      "y2": 1200
+     }
+    },
+    {
+     "id": "a8lb",
+     "type": "line",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 0,
+     "height": 0,
+     "properties": {
+      "x1": 450,
+      "y1": 0,
+      "x2": 450,
+      "y2": 1200
+     }
+    }
+   ]
+  },
+  {
+   "id": "arch-9",
+   "name": "Säule Ø50",
+   "elements": [
+    {
+     "id": "a9a",
+     "type": "circle",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 500,
+     "height": 500,
+     "properties": {
+      "radius": 250,
+      "fill": "#9aa0a6"
+     }
+    }
+   ]
+  },
+  {
+   "id": "arch-10",
+   "name": "Schreibtisch",
+   "elements": [
+    {
+     "id": "a10a",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 1800,
+     "height": 800,
+     "properties": {
+      "fill": "#6b7280"
+     }
+    }
+   ]
+  },
+  {
+   "id": "arch-11",
+   "name": "Bürostuhl",
+   "elements": [
+    {
+     "id": "a11a",
+     "type": "chair",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 60,
+     "height": 60,
+     "properties": {
+      "fill": "#5a7d9a",
+      "outlineColor": "#2a5a99"
+     }
+    }
+   ]
+  },
+  {
+   "id": "arch-12",
+   "name": "Sofa 3-Sitzer",
+   "elements": [
+    {
+     "id": "a12a",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 2200,
+     "height": 900,
+     "properties": {
+      "fill": "#5a7d9a"
+     }
+    }
+   ]
+  },
+  {
+   "id": "arch-13",
+   "name": "Einzelbett",
+   "elements": [
+    {
+     "id": "a13a",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 900,
+     "height": 2000,
+     "properties": {
+      "fill": "#8fa3bf"
+     }
+    },
+    {
+     "id": "a13b",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": -750,
+     "width": 700,
+     "height": 300,
+     "properties": {
+      "fill": "#d5dbdb"
+     }
+    }
+   ]
+  },
+  {
+   "id": "arch-14",
+   "name": "Waschbecken",
+   "elements": [
+    {
+     "id": "a14a",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 600,
+     "height": 450,
+     "properties": {}
+    },
+    {
+     "id": "a14b",
+     "type": "circle",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 340,
+     "height": 340,
+     "properties": {
+      "radius": 170,
+      "fill": "#7f9db9"
+     }
+    }
+   ]
+  },
+  {
+   "id": "arch-15",
+   "name": "Küchenzeile 2.4m",
+   "elements": [
+    {
+     "id": "a15a",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 2400,
+     "height": 600,
+     "properties": {
+      "fill": "#3c4043"
+     }
+    },
+    {
+     "id": "a15p0",
+     "type": "circle",
+     "layerId": "layer-0",
+     "x": -1800,
+     "y": 0,
+     "width": 180,
+     "height": 180,
+     "properties": {
+      "radius": 90,
+      "fill": "#202124"
+     }
+    },
+    {
+     "id": "a15p1",
+     "type": "circle",
+     "layerId": "layer-0",
+     "x": -1320,
+     "y": 0,
+     "width": 180,
+     "height": 180,
+     "properties": {
+      "radius": 90,
+      "fill": "#202124"
+     }
+    },
+    {
+     "id": "a15p2",
+     "type": "circle",
+     "layerId": "layer-0",
+     "x": -840,
+     "y": 0,
+     "width": 180,
+     "height": 180,
+     "properties": {
+      "radius": 90,
+      "fill": "#202124"
+     }
+    },
+    {
+     "id": "a15p3",
+     "type": "circle",
+     "layerId": "layer-0",
+     "x": -360,
+     "y": 0,
+     "width": 180,
+     "height": 180,
+     "properties": {
+      "radius": 90,
+      "fill": "#202124"
+     }
+    }
+   ]
+  }
+ ]
+}

frontend/src/plugins/builtin/library/catalogs/event.json

@@ -0,0 +1,619 @@
+{
+ "folderId": "cat-event",
+ "label": "Event-Katalog",
+ "blocks": [
+  {
+   "id": "evt-1",
+   "name": "Stuhl",
+   "elements": [
+    {
+     "id": "e1",
+     "type": "chair",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 45,
+     "height": 45,
+     "properties": {
+      "fill": "#4a90d9",
+      "outlineColor": "#2a5a99"
+     }
+    }
+   ]
+  },
+  {
+   "id": "evt-2",
+   "name": "Tisch rund 180cm",
+   "elements": [
+    {
+     "id": "e2a",
+     "type": "table",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 1800,
+     "height": 1800,
+     "properties": {
+      "fill": "#8b7355"
+     }
+    }
+   ]
+  },
+  {
+   "id": "evt-3",
+   "name": "Tisch rund 120cm",
+   "elements": [
+    {
+     "id": "e3a",
+     "type": "table",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 1200,
+     "height": 1200,
+     "properties": {
+      "fill": "#8b7355"
+     }
+    }
+   ]
+  },
+  {
+   "id": "evt-4",
+   "name": "Stehtisch 80cm",
+   "elements": [
+    {
+     "id": "e4a",
+     "type": "table",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 800,
+     "height": 800,
+     "properties": {
+      "fill": "#a08f6a"
+     }
+    }
+   ]
+  },
+  {
+   "id": "evt-5",
+   "name": "Bühne 3x2m",
+   "elements": [
+    {
+     "id": "e5a",
+     "type": "stage",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 3000,
+     "height": 2000,
+     "properties": {}
+    }
+   ]
+  },
+  {
+   "id": "evt-6",
+   "name": "Bühne 4x3m",
+   "elements": [
+    {
+     "id": "e6a",
+     "type": "stage",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 4000,
+     "height": 3000,
+     "properties": {}
+    }
+   ]
+  },
+  {
+   "id": "evt-7",
+   "name": "Podest 1x1m",
+   "elements": [
+    {
+     "id": "e7a",
+     "type": "stage",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 1000,
+     "height": 1000,
+     "properties": {}
+    }
+   ]
+  },
+  {
+   "id": "evt-8",
+   "name": "Sitzreihe (10 Stühle)",
+   "elements": [
+    {
+     "id": "e2",
+     "type": "chair",
+     "layerId": "layer-0",
+     "x": -405,
+     "y": 0,
+     "width": 45,
+     "height": 45,
+     "properties": {
+      "fill": "#4a90d9",
+      "outlineColor": "#2a5a99"
+     }
+    },
+    {
+     "id": "e3",
+     "type": "chair",
+     "layerId": "layer-0",
+     "x": -315,
+     "y": 0,
+     "width": 45,
+     "height": 45,
+     "properties": {
+      "fill": "#4a90d9",
+      "outlineColor": "#2a5a99"
+     }
+    },
+    {
+     "id": "e4",
+     "type": "chair",
+     "layerId": "layer-0",
+     "x": -225,
+     "y": 0,
+     "width": 45,
+     "height": 45,
+     "properties": {
+      "fill": "#4a90d9",
+      "outlineColor": "#2a5a99"
+     }
+    },
+    {
+     "id": "e5",
+     "type": "chair",
+     "layerId": "layer-0",
+     "x": -135,
+     "y": 0,
+     "width": 45,
+     "height": 45,
+     "properties": {
+      "fill": "#4a90d9",
+      "outlineColor": "#2a5a99"
+     }
+    },
+    {
+     "id": "e6",
+     "type": "chair",
+     "layerId": "layer-0",
+     "x": -45,
+     "y": 0,
+     "width": 45,
+     "height": 45,
+     "properties": {
+      "fill": "#4a90d9",
+      "outlineColor": "#2a5a99"
+     }
+    },
+    {
+     "id": "e7",
+     "type": "chair",
+     "layerId": "layer-0",
+     "x": 45,
+     "y": 0,
+     "width": 45,
+     "height": 45,
+     "properties": {
+      "fill": "#4a90d9",
+      "outlineColor": "#2a5a99"
+     }
+    },
+    {
+     "id": "e8",
+     "type": "chair",
+     "layerId": "layer-0",
+     "x": 135,
+     "y": 0,
+     "width": 45,
+     "height": 45,
+     "properties": {
+      "fill": "#4a90d9",
+      "outlineColor": "#2a5a99"
+     }
+    },
+    {
+     "id": "e9",
+     "type": "chair",
+     "layerId": "layer-0",
+     "x": 225,
+     "y": 0,
+     "width": 45,
+     "height": 45,
+     "properties": {
+      "fill": "#4a90d9",
+      "outlineColor": "#2a5a99"
+     }
+    },
+    {
+     "id": "e10",
+     "type": "chair",
+     "layerId": "layer-0",
+     "x": 315,
+     "y": 0,
+     "width": 45,
+     "height": 45,
+     "properties": {
+      "fill": "#4a90d9",
+      "outlineColor": "#2a5a99"
+     }
+    },
+    {
+     "id": "e11",
+     "type": "chair",
+     "layerId": "layer-0",
+     "x": 405,
+     "y": 0,
+     "width": 45,
+     "height": 45,
+     "properties": {
+      "fill": "#4a90d9",
+      "outlineColor": "#2a5a99"
+     }
+    }
+   ]
+  },
+  {
+   "id": "evt-9",
+   "name": "Bankett-Rundtisch (8 Stühle)",
+   "elements": [
+    {
+     "id": "e9a",
+     "type": "circle",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 1800,
+     "height": 1800,
+     "properties": {
+      "radius": 900,
+      "fill": "#8b7355"
+     }
+    },
+    {
+     "id": "e12",
+     "type": "chair",
+     "layerId": "layer-0",
+     "x": 1200,
+     "y": 0,
+     "width": 45,
+     "height": 45,
+     "properties": {
+      "fill": "#4a90d9",
+      "outlineColor": "#2a5a99"
+     }
+    },
+    {
+     "id": "e13",
+     "type": "chair",
+     "layerId": "layer-0",
+     "x": 848,
+     "y": 848,
+     "width": 45,
+     "height": 45,
+     "properties": {
+      "fill": "#4a90d9",
+      "outlineColor": "#2a5a99"
+     }
+    },
+    {
+     "id": "e14",
+     "type": "chair",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 1200,
+     "width": 45,
+     "height": 45,
+     "properties": {
+      "fill": "#4a90d9",
+      "outlineColor": "#2a5a99"
+     }
+    },
+    {
+     "id": "e15",
+     "type": "chair",
+     "layerId": "layer-0",
+     "x": -848,
+     "y": 848,
+     "width": 45,
+     "height": 45,
+     "properties": {
+      "fill": "#4a90d9",
+      "outlineColor": "#2a5a99"
+     }
+    },
+    {
+     "id": "e16",
+     "type": "chair",
+     "layerId": "layer-0",
+     "x": -1200,
+     "y": 0,
+     "width": 45,
+     "height": 45,
+     "properties": {
+      "fill": "#4a90d9",
+      "outlineColor": "#2a5a99"
+     }
+    },
+    {
+     "id": "e17",
+     "type": "chair",
+     "layerId": "layer-0",
+     "x": -848,
+     "y": -848,
+     "width": 45,
+     "height": 45,
+     "properties": {
+      "fill": "#4a90d9",
+      "outlineColor": "#2a5a99"
+     }
+    },
+    {
+     "id": "e18",
+     "type": "chair",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": -1200,
+     "width": 45,
+     "height": 45,
+     "properties": {
+      "fill": "#4a90d9",
+      "outlineColor": "#2a5a99"
+     }
+    },
+    {
+     "id": "e19",
+     "type": "chair",
+     "layerId": "layer-0",
+     "x": 848,
+     "y": -848,
+     "width": 45,
+     "height": 45,
+     "properties": {
+      "fill": "#4a90d9",
+      "outlineColor": "#2a5a99"
+     }
+    }
+   ]
+  },
+  {
+   "id": "evt-10",
+   "name": "Tischgruppe (4 Stühle)",
+   "elements": [
+    {
+     "id": "e10a",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 1600,
+     "height": 800,
+     "properties": {
+      "fill": "#8b7355"
+     }
+    },
+    {
+     "id": "e20",
+     "type": "chair",
+     "layerId": "layer-0",
+     "x": -400,
+     "y": -580,
+     "width": 45,
+     "height": 45,
+     "properties": {
+      "fill": "#4a90d9",
+      "outlineColor": "#2a5a99"
+     }
+    },
+    {
+     "id": "e21",
+     "type": "chair",
+     "layerId": "layer-0",
+     "x": 400,
+     "y": -580,
+     "width": 45,
+     "height": 45,
+     "properties": {
+      "fill": "#4a90d9",
+      "outlineColor": "#2a5a99"
+     }
+    },
+    {
+     "id": "e22",
+     "type": "chair",
+     "layerId": "layer-0",
+     "x": -400,
+     "y": 580,
+     "width": 45,
+     "height": 45,
+     "properties": {
+      "fill": "#4a90d9",
+      "outlineColor": "#2a5a99"
+     }
+    },
+    {
+     "id": "e23",
+     "type": "chair",
+     "layerId": "layer-0",
+     "x": 400,
+     "y": 580,
+     "width": 45,
+     "height": 45,
+     "properties": {
+      "fill": "#4a90d9",
+      "outlineColor": "#2a5a99"
+     }
+    }
+   ]
+  },
+  {
+   "id": "evt-11",
+   "name": "Flipchart",
+   "elements": [
+    {
+     "id": "e11a",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 700,
+     "height": 500,
+     "properties": {
+      "fill": "#546b7a"
+     }
+    },
+    {
+     "id": "e11b",
+     "type": "line",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 0,
+     "height": 0,
+     "properties": {
+      "x1": 0,
+      "y1": 250,
+      "x2": 0,
+      "y2": 500
+     }
+    }
+   ]
+  },
+  {
+   "id": "evt-12",
+   "name": "Pinnwand 120cm",
+   "elements": [
+    {
+     "id": "e12a",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 1200,
+     "height": 150,
+     "properties": {
+      "fill": "#7a6550"
+     }
+    }
+   ]
+  },
+  {
+   "id": "evt-13",
+   "name": "Kaffeetafel 2m",
+   "elements": [
+    {
+     "id": "e13a",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 2000,
+     "height": 600,
+     "properties": {
+      "fill": "#6b5340"
+     }
+    }
+   ]
+  },
+  {
+   "id": "evt-14",
+   "name": "Garderobe 1m",
+   "elements": [
+    {
+     "id": "e14a",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 1000,
+     "height": 300,
+     "properties": {}
+    },
+    {
+     "id": "e14h0",
+     "type": "circle",
+     "layerId": "layer-0",
+     "x": -300,
+     "y": 0,
+     "width": 180,
+     "height": 180,
+     "properties": {
+      "radius": 90
+     }
+    },
+    {
+     "id": "e14h1",
+     "type": "circle",
+     "layerId": "layer-0",
+     "x": -150,
+     "y": 0,
+     "width": 180,
+     "height": 180,
+     "properties": {
+      "radius": 90
+     }
+    },
+    {
+     "id": "e14h2",
+     "type": "circle",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 180,
+     "height": 180,
+     "properties": {
+      "radius": 90
+     }
+    },
+    {
+     "id": "e14h3",
+     "type": "circle",
+     "layerId": "layer-0",
+     "x": 150,
+     "y": 0,
+     "width": 180,
+     "height": 180,
+     "properties": {
+      "radius": 90
+     }
+    },
+    {
+     "id": "e14h4",
+     "type": "circle",
+     "layerId": "layer-0",
+     "x": 300,
+     "y": 0,
+     "width": 180,
+     "height": 180,
+     "properties": {
+      "radius": 90
+     }
+    }
+   ]
+  },
+  {
+   "id": "evt-15",
+   "name": "Teppichläufer 2m",
+   "elements": [
+    {
+     "id": "e15a",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 2000,
+     "height": 200,
+     "properties": {
+      "fill": "#7a5230"
+     }
+    }
+   ]
+  }
+ ]
+}

frontend/src/plugins/builtin/library/catalogs/landscape.json

@@ -0,0 +1,406 @@
+{
+ "folderId": "cat-land",
+ "label": "Landschafts-Katalog",
+ "blocks": [
+  {
+   "id": "land-1",
+   "name": "Baum (groß)",
+   "elements": [
+    {
+     "id": "l1a",
+     "type": "circle",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": -200,
+     "width": 2200,
+     "height": 2200,
+     "properties": {
+      "radius": 1100,
+      "fill": "#6aa84f"
+     }
+    },
+    {
+     "id": "l1b",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 600,
+     "width": 200,
+     "height": 800,
+     "properties": {
+      "fill": "#8b5a2b"
+     }
+    }
+   ]
+  },
+  {
+   "id": "land-2",
+   "name": "Baum (mittel)",
+   "elements": [
+    {
+     "id": "l2a",
+     "type": "circle",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": -150,
+     "width": 1500,
+     "height": 1500,
+     "properties": {
+      "radius": 750,
+      "fill": "#6aa84f"
+     }
+    },
+    {
+     "id": "l2b",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 450,
+     "width": 150,
+     "height": 600,
+     "properties": {
+      "fill": "#8b5a2b"
+     }
+    }
+   ]
+  },
+  {
+   "id": "land-3",
+   "name": "Strauch",
+   "elements": [
+    {
+     "id": "l3a",
+     "type": "circle",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 1000,
+     "height": 1000,
+     "properties": {
+      "radius": 500,
+      "fill": "#85b75f"
+     }
+    }
+   ]
+  },
+  {
+   "id": "land-4",
+   "name": "Hecke horizontal 4m",
+   "elements": [
+    {
+     "id": "l4a",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 4000,
+     "height": 500,
+     "properties": {
+      "fill": "#4c7a3f"
+     }
+    }
+   ]
+  },
+  {
+   "id": "land-5",
+   "name": "Hecke vertikal 4m",
+   "elements": [
+    {
+     "id": "l5a",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 500,
+     "height": 4000,
+     "properties": {
+      "fill": "#4c7a3f"
+     }
+    }
+   ]
+  },
+  {
+   "id": "land-6",
+   "name": "Blumenbeet",
+   "elements": [
+    {
+     "id": "l6a",
+     "type": "circle",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 1600,
+     "height": 1600,
+     "properties": {
+      "radius": 800,
+      "fill": "#c76fb6"
+     }
+    },
+    {
+     "id": "l6b",
+     "type": "circle",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 600,
+     "height": 600,
+     "properties": {
+      "radius": 300,
+      "fill": "#e6a23c"
+     }
+    }
+   ]
+  },
+  {
+   "id": "land-7",
+   "name": "Teich",
+   "elements": [
+    {
+     "id": "l7a",
+     "type": "circle",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 3000,
+     "height": 3000,
+     "properties": {
+      "radius": 1500,
+      "fill": "#4a90d9"
+     }
+    },
+    {
+     "id": "l7b",
+     "type": "circle",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 100,
+     "width": 2700,
+     "height": 2700,
+     "properties": {
+      "radius": 1350,
+      "fill": "#5fa8e0"
+     }
+    }
+   ]
+  },
+  {
+   "id": "land-8",
+   "name": "Rasenfläche 5x3m",
+   "elements": [
+    {
+     "id": "l8a",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 5000,
+     "height": 3000,
+     "properties": {
+      "fill": "#7cb342"
+     }
+    }
+   ]
+  },
+  {
+   "id": "land-9",
+   "name": "Bodenplatte",
+   "elements": [
+    {
+     "id": "l9a",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 1200,
+     "height": 1200,
+     "properties": {
+      "fill": "#b8a888"
+     }
+    }
+   ]
+  },
+  {
+   "id": "land-10",
+   "name": "Weg (Gerade)",
+   "elements": [
+    {
+     "id": "l10a",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 600,
+     "height": 4000,
+     "properties": {
+      "fill": "#b8a888"
+     }
+    }
+   ]
+  },
+  {
+   "id": "land-11",
+   "name": "Sonnenliege",
+   "elements": [
+    {
+     "id": "l11a",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 600,
+     "height": 2000,
+     "properties": {
+      "fill": "#d2b48c"
+     }
+    }
+   ]
+  },
+  {
+   "id": "land-12",
+   "name": "Feuerschale",
+   "elements": [
+    {
+     "id": "l12a",
+     "type": "circle",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 1200,
+     "height": 1200,
+     "properties": {
+      "radius": 600,
+      "fill": "#5a5a5a"
+     }
+    },
+    {
+     "id": "l12b",
+     "type": "circle",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 600,
+     "height": 600,
+     "properties": {
+      "radius": 300,
+      "fill": "#cc4125"
+     }
+    }
+   ]
+  },
+  {
+   "id": "land-13",
+   "name": "Zaun 3m",
+   "elements": [
+    {
+     "id": "l13a",
+     "type": "line",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 0,
+     "height": 0,
+     "properties": {
+      "x1": -1500,
+      "y1": 0,
+      "x2": -1500,
+      "y2": 900
+     }
+    },
+    {
+     "id": "l13b",
+     "type": "line",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 0,
+     "height": 0,
+     "properties": {
+      "x1": 1500,
+      "y1": 0,
+      "x2": 1500,
+      "y2": 900
+     }
+    },
+    {
+     "id": "l13c",
+     "type": "line",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 0,
+     "height": 0,
+     "properties": {
+      "x1": -1500,
+      "y1": 450,
+      "x2": 1500,
+      "y2": 450
+     }
+    }
+   ]
+  },
+  {
+   "id": "land-14",
+   "name": "Laterne",
+   "elements": [
+    {
+     "id": "l14a",
+     "type": "circle",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": -1000,
+     "width": 400,
+     "height": 400,
+     "properties": {
+      "radius": 200,
+      "fill": "#f5d76e"
+     }
+    },
+    {
+     "id": "l14b",
+     "type": "line",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 0,
+     "height": 0,
+     "properties": {
+      "x1": 0,
+      "y1": -800,
+      "x2": 0,
+      "y2": 1000
+     }
+    },
+    {
+     "id": "l14c",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 1100,
+     "width": 300,
+     "height": 200,
+     "properties": {
+      "fill": "#5a5a5a"
+     }
+    }
+   ]
+  },
+  {
+   "id": "land-15",
+   "name": "Gartenbank",
+   "elements": [
+    {
+     "id": "l15a",
+     "type": "rect",
+     "layerId": "layer-0",
+     "x": 0,
+     "y": 0,
+     "width": 1500,
+     "height": 400,
+     "properties": {
+      "fill": "#8b5a2b"
+     }
+    }
+   ]
+  }
+ ]
+}

frontend/src/plugins/builtin/library/index.ts

@@ -0,0 +1,24 @@
+/**
+ * Task F4 – Builtin-Bibliotheks-Plugin.
+ *
+ * Registriert den builtin-Katalog-Provider über die Plugin-API v2. Die Provider
+ * für user-library (zeichnungsscoped) und global-library (API/Token) sind als
+ * Fabriken (makeUserLibraryProvider / makeGlobalLibraryProvider) umgesetzt und
+ * werden vom UI je Token/Zeichnung instanziert.
+ */
+import type { PluginV2 } from '../../types';
+import { builtinCatalogProvider } from './providers';
+
+export const builtinLibraryPlugin: PluginV2 = {
+  manifest: {
+    id: 'builtin-library',
+    name: 'Block-Bibliothek',
+    version: '1.0.0',
+    author: 'WebCAD Project',
+    description: 'Bibliothek: builtin-Kataloge (Event/Architektur/Landschaft) als LibraryProvider (Task F4).',
+    category: 'library',
+    enabledByDefault: true,
+    permissions: ['storage'],
+  },
+  libraryProviders: [builtinCatalogProvider],
+};

frontend/src/plugins/builtin/library/providers.ts

@@ -0,0 +1,161 @@
+/**
+ * Task F4 – Bibliotheksquellen als LibraryProviderExtension.
+ *
+ * Drei Quellen:
+ * - builtinCatalogProvider: statische JSON-Startersets (event/architecture/landscape)
+ * - makeUserLibraryProvider: zeichnungsscoped Blockdefinitionen (Drawing-Blöcke)
+ * - makeGlobalLibraryProvider: persistente globale Blockbibliothek (global-blocks API)
+ *
+ * Payload-Konvention: String-Payload = JSON-Array von CADElementen — identisch zum
+ * 'text/global-block-data' Drop-Kanal von BlockLibraryTree (F2/F3), damit der
+ * Canvas-Drop-Pfad (CanvasArea) ohne Änderung funktioniert.
+ */
+import catalogEvent from './catalogs/event.json';
+import catalogArch from './catalogs/architecture.json';
+import catalogLand from './catalogs/landscape.json';
+import { generateBlockSvg } from '../../../utils/blockThumbnail';
+import type { CADElement } from '../../../types/cad.types';
+import type { LibraryProviderExtension, LibBlock, LibFolder } from '../../types';
+import { getGlobalFolders, getGlobalBlocks, type GlobalBlock } from '../../../services/api';
+
+interface CatalogBlock { id: string; name: string; elements: CADElement[]; }
+interface CatalogFile { folderId: string; label: string; blocks: CatalogBlock[]; }
+
+const CATALOGS: CatalogFile[] = [catalogEvent, catalogArch, catalogLand].map(
+  (c) => c as unknown as CatalogFile,
+);
+
+const thumbCache = new Map<string, string>();
+
+function toLibBlock(folderId: string, block: CatalogBlock): LibBlock {
+  let thumbnail = thumbCache.get(block.id);
+  if (!thumbnail) {
+    thumbnail = generateBlockSvg(block.elements);
+    thumbCache.set(block.id, thumbnail);
+  }
+  return {
+    id: block.id,
+    folderId,
+    name: block.name,
+    thumbnail,
+    payload: JSON.stringify(block.elements),
+  };
+}
+
+/** Statischer builtin-Katalog: Event / Architektur / Landschaft Startersets. */
+export const builtinCatalogProvider: LibraryProviderExtension = {
+  id: 'builtin-catalog',
+  label: 'Builtin-Kataloge',
+  async listFolders(): Promise<LibFolder[]> {
+    return CATALOGS.map((c) => ({ id: c.folderId, label: c.label, parentId: null }));
+  },
+  async listBlocks(folderId: string): Promise<LibBlock[]> {
+    const cat = CATALOGS.find((c) => c.folderId === folderId);
+    return cat ? cat.blocks.map((b) => toLibBlock(folderId, b)) : [];
+  },
+  async getBlock(id: string): Promise<LibBlock> {
+    for (const cat of CATALOGS) {
+      const found = cat.blocks.find((b) => b.id === id);
+      if (found) return toLibBlock(cat.folderId, found);
+    }
+    throw new Error(`Block not found: ${id}`);
+  },
+};
+
+export interface UserBlockLike {
+  id: string;
+  name: string;
+  elements?: unknown;
+  elements_json?: string;
+  thumbnail?: string | null;
+  drawing_id?: string;
+  description?: string | null;
+  category?: string;
+}
+
+function extractElements(block: UserBlockLike): CADElement[] {
+  try {
+    if (Array.isArray(block.elements)) return block.elements as CADElement[];
+    if (typeof block.elements_json === 'string') {
+      const parsed: unknown = JSON.parse(block.elements_json);
+      if (Array.isArray(parsed)) return parsed as CADElement[];
+      const wrapped = parsed as { elements?: unknown } | null;
+      if (wrapped && Array.isArray(wrapped.elements)) return wrapped.elements as CADElement[];
+    }
+  } catch {
+    // invalider Inhalt → leerer Block wird beim Auflisten gefiltert
+  }
+  return [];
+}
+
+/** Zeichnungsscoped Blöcke (Drawing-Blöcke) als Bibliothek anbinden. */
+export function makeUserLibraryProvider(userBlocks: readonly UserBlockLike[]): LibraryProviderExtension {
+  const folderId = 'user-blocks';
+  const toBlock = (block: UserBlockLike): LibBlock => {
+    const elements = extractElements(block);
+    return {
+      id: `user:${block.id}`,
+      folderId,
+      name: block.name,
+      thumbnail: elements.length ? generateBlockSvg(elements) : undefined,
+      payload: elements.length ? JSON.stringify(elements) : undefined,
+    };
+  };
+  return {
+    id: 'user-library',
+    label: 'Benutzer-Bibliothek',
+    async listFolders(): Promise<LibFolder[]> {
+      return [{ id: folderId, label: 'Zeichnungs-Blöcke', parentId: null }];
+    },
+    async listBlocks(id: string): Promise<LibBlock[]> {
+      return id === folderId
+        ? userBlocks.filter((b) => extractElements(b).length > 0).map(toBlock)
+        : [];
+    },
+    async getBlock(id: string): Promise<LibBlock> {
+      const found = userBlocks.find((b) => `user:${b.id}` === id && extractElements(b).length > 0);
+      if (found) return toBlock(found);
+      throw new Error(`Block not found: ${id}`);
+    },
+  };
+}
+
+/** Persistente globale Blockbibliothek über die global-blocks API anbinden. */
+export function makeGlobalLibraryProvider(token: string): LibraryProviderExtension {
+  const toBlock = (block: GlobalBlock): LibBlock => ({
+    id: `global:${block.id}`,
+    folderId: block.folder_id ?? 'global-root',
+    name: block.name,
+    thumbnail: block.svg_data ?? undefined,
+    payload: block.block_data,
+  });
+  const loadAll = async (): Promise<GlobalBlock[]> => {
+    try {
+      return await getGlobalBlocks(token);
+    } catch {
+      return [];
+    }
+  };
+  return {
+    id: 'global-library',
+    label: 'Globale Bibliothek',
+    async listFolders(): Promise<LibFolder[]> {
+      try {
+        const folders = await getGlobalFolders(token);
+        return folders.map((f) => ({ id: f.id, label: f.name, parentId: f.parent_id }));
+      } catch {
+        return [];
+      }
+    },
+    async listBlocks(folderId: string): Promise<LibBlock[]> {
+      const blocks = await loadAll();
+      return blocks.filter((b) => (b.folder_id ?? 'global-root') === folderId).map(toBlock);
+    },
+    async getBlock(id: string): Promise<LibBlock> {
+      const blocks = await loadAll();
+      const found = blocks.find((b) => `global:${b.id}` === id);
+      if (found) return toBlock(found);
+      throw new Error(`Block not found: ${id}`);
+    },
+  };
+}

frontend/src/plugins/index.ts

@@ -12,15 +12,46 @@ export type {
   CommandExtension,
   ImportExportExtension,
   PropertyField,
+  // API v2 (Task A1):
+  PluginV2,
+  ToolExtensionV2,
+  ToolManifestPart,
+  ToolPointerEvent,
+  ToolContext,
+  PanelExtension,
+  LibraryProviderExtension,
+  LibFolder,
+  LibBlock,
+  PluginCategoryV2,
 } from './types';
 
 // Built-in plugins
 export { eventToolsPlugin } from './builtin/eventTools';
+export { coreDrawingPlugin } from './builtin/core-drawing';
+export { coreModifyPlugin } from './builtin/core-modify';
+export { coreAnnotatePlugin } from './builtin/core-annotate';
+export { coreMeasurePlugin } from './builtin/core-measure';
+export { eventToolsV2Plugin } from './builtin/event-tools';
+export { builtinLibraryPlugin } from './builtin/library';
+export { builtinCatalogProvider, makeUserLibraryProvider, makeGlobalLibraryProvider } from './builtin/library/providers';
 
 import { pluginRegistry } from './PluginRegistry';
 import { eventToolsPlugin } from './builtin/eventTools';
+import { coreDrawingPlugin } from './builtin/core-drawing';
+import { coreModifyPlugin } from './builtin/core-modify';
+import { coreAnnotatePlugin } from './builtin/core-annotate';
+import { coreMeasurePlugin } from './builtin/core-measure';
+import { eventToolsV2Plugin } from './builtin/event-tools';
+import { builtinLibraryPlugin } from './builtin/library';
 
 /** Register all built-in plugins */
 export function registerBuiltinPlugins() {
   pluginRegistry.register(eventToolsPlugin);
+  // API v2 (Task A3+):
+  pluginRegistry.registerV2(coreDrawingPlugin);
+  pluginRegistry.registerV2(coreModifyPlugin);
+  pluginRegistry.registerV2(coreAnnotatePlugin);
+  pluginRegistry.registerV2(coreMeasurePlugin);
+  pluginRegistry.registerV2(eventToolsV2Plugin);
+  pluginRegistry.registerV2(builtinLibraryPlugin);
 }

frontend/src/plugins/types.ts

@@ -116,3 +116,133 @@ export interface PluginState {
   enabled: boolean;
   loaded: boolean;
 }
+
+// ═══════════════════════════════════════════════════════
+// ─── API v2 (Task A1, additiv — siehe ROADMAP TEIL 2.4) ──
+// ═══════════════════════════════════════════════════════
+import type { Pt } from '../tools/modification/geometry';
+
+/** Manifest-Teil eines V2-Werkzeugs. */
+export interface ToolManifestPart {
+  id: string;
+  label: string;
+  icon: string;
+  ribbonTab: string;
+  shortcut?: string;
+  /** 'basic' = auch im Einfach-Modus sichtbar (Task H1). */
+  tags?: Array<'basic' | 'pro'>;
+}
+
+/** Normalisiertes Pointer-Event mit Welt- und Bildschirmkoordinaten. */
+export interface ToolPointerEvent {
+  world: Pt;
+  screen: Pt;
+  button: number;
+  shift: boolean;
+  alt: boolean;
+  ctrl: boolean;
+}
+
+/** Kontext, den der Dispatcher einem aktiven V2-Tool übergibt. */
+export interface ToolContext {
+  /** Aktueller Optionsstand für dieses Tool (aus toolStore). */
+  options: Record<string, unknown>;
+  /** Statuszeilentext setzen. */
+  setStatus(msg: string): void;
+  /** Live-Vorschau setzen (null = Vorschau entfernen). Ab A3 an Renderer angebunden. */
+  setPreview?(el: CADElement | null): void;
+}
+
+/** Selektions-/Treffer-Bridge für Werkzeuge (ab A3, von CanvasArea injiziert). */
+export interface ToolSelectionBridge {
+  /** Aktuell selektierte Element-IDs. */
+  getIds(): string[];
+  /** Setzt die Selektion vollständig. */
+  setIds(ids: string[]): void;
+  /** Element-Treffer an Weltposition (oder null). */
+  hitTest(worldX: number, worldY: number, tolerancePx: number): CADElement | null;
+}
+
+/** Erweiterter Kontext für Tools mit Dokument-/Selektionszugriff (A3). */
+export interface FullToolContext extends ToolContext {
+  /** Dokumentzugriff (transact/add/update/delete). */
+  doc?: import('../kernel/document/CADDocument').CADDocument;
+  /** Selektion + HitTest-Bridge. */
+  selection?: ToolSelectionBridge;
+}
+
+/** V2-Werkzeug mit eigenen Pointer-Handlern (ersetzt langfristig ToolExtension). */
+export interface ToolExtensionV2 {
+  manifest: ToolManifestPart & { description?: string };
+  /** Optionsleisten-Schema (wiederverwendet PropertyField). */
+  optionsSchema: PropertyField[];
+  handlers: {
+    down?(e: ToolPointerEvent, ctx: ToolContext): void;
+    move?(e: ToolPointerEvent, ctx: ToolContext): void;
+    up?(e: ToolPointerEvent, ctx: ToolContext): void;
+    /** true = Tastendruck konsumiert. */
+    key?(e: KeyboardEvent, ctx: ToolContext): boolean;
+    /** ESC / Rechtsklick. */
+    cancel?(ctx: ToolContext): void;
+  };
+}
+
+/** Eigenes Sidebar-Panel eines Plugins. */
+export interface PanelExtension {
+  id: string;
+  title: string;
+  slot: 'left' | 'right';
+  render(): HTMLElement;
+}
+
+/** Ordner einer Bibliothek (LibraryProvider). */
+export interface LibFolder {
+  id: string;
+  label: string;
+  parentId: string | null;
+}
+
+/** Block einer Bibliothek (Metadaten; Payload provider-spezifisch). */
+export interface LibBlock {
+  id: string;
+  folderId: string;
+  name: string;
+  tags?: string[];
+  thumbnail?: string; // svg/dataURL
+  /** Payload für Canvas-Drop: i.d.R. JSON-String eines CADElement-Arrays (Task F4). */
+  payload?: unknown;
+}
+
+/** Liefert Kataloge — Kern der Plugin-erweiterbaren Library (Phase F). */
+export interface LibraryProviderExtension {
+  id: string;
+  label: string;
+  listFolders(): Promise<LibFolder[]>;
+  listBlocks(folderId: string): Promise<LibBlock[]>;
+  getBlock(id: string): Promise<LibBlock>;
+}
+
+/** Erweiterte Manifest-Kategorie inkl. library. */
+export type PluginCategoryV2 = PluginManifest['category'] | 'library';
+
+/** Plugin-API v2 (registriert parallel zum alten Plugin-Interface). */
+export interface PluginV2 {
+  manifest: {
+    id: string;
+    name: string;
+    version: string;
+    author: string;
+    description: string;
+    category: PluginCategoryV2;
+    enabledByDefault?: boolean;
+    minAppVersion?: string;
+    permissions?: Array<'canvas' | 'network' | 'storage'>;
+  };
+  tools?: ToolExtensionV2[];
+  panels?: PanelExtension[];
+  libraryProviders?: LibraryProviderExtension[];
+  onInit?(): void;
+  onActivate?(): void;
+  onDeactivate?(): void;
+  onDestroy?(): void;
+}

frontend/src/render/mock/MockAdapter.ts

@@ -0,0 +1,123 @@
+/**
+ * MockAdapter – Headless-Implementierung des RenderAdapter (Task C1).
+ * Zeichnet nichts; protokolliert alle Aufrufe für assertions in Unit-Tests.
+ */
+import type {
+  RenderAdapter,
+  Viewport,
+  GridConfig,
+  BackgroundDrawConfig,
+  RulerConfig,
+  LayerStyle,
+  OverlayPainter,
+  SelectionState,
+} from '../types';
+import type { CADElement, CADLayer } from '../../types/cad.types';
+import type { Pt } from '../../tools/modification/geometry';
+
+export interface RecordedCall {
+  method: string;
+  args: unknown[];
+}
+
+export class MockAdapter implements RenderAdapter {
+  readonly calls: RecordedCall[] = [];
+  private canvas: HTMLCanvasElement | null = null;
+  nextHitTestResult: CADElement | null = null;
+
+  // ── Recording helper ─────────────────────────────────────
+
+  private rec(method: string, args: unknown[]): void {
+    this.calls.push({ method, args });
+  }
+
+  /** Test-Helfer: alle Aufrufe einer Methode. */
+  callsOf(method: string): RecordedCall[] {
+    return this.calls.filter((c) => c.method === method);
+  }
+
+  /** Test-Helfer: Anzahl Aufrufe einer Methode. */
+  countCalls(method: string): number {
+    return this.callsOf(method).length;
+  }
+
+  reset(): void {
+    this.calls.length = 0;
+    this.nextHitTestResult = null;
+  }
+
+  // ── RenderAdapter Implementierung (reines Recording) ─────
+
+  init(canvas: HTMLCanvasElement): void {
+    this.canvas = canvas;
+    this.rec('init', [canvas]);
+  }
+
+  resize(width: number, height: number, dpr: number): void {
+    this.rec('resize', [width, height, dpr]);
+  }
+
+  setViewport(vp: Viewport): void {
+    this.rec('setViewport', [vp]);
+  }
+
+  destroy(): void {
+    this.rec('destroy', []);
+  }
+
+  clear(color: string): void {
+    this.rec('clear', [color]);
+  }
+
+  drawGrid(cfg: GridConfig): void {
+    this.rec('drawGrid', [cfg]);
+  }
+
+  drawBackground(img: HTMLImageElement | null, cfg: BackgroundDrawConfig): void {
+    this.rec('drawBackground', [img, cfg]);
+  }
+
+  drawRuler(cfg: RulerConfig): void {
+    this.rec('drawRuler', [cfg]);
+  }
+
+  drawElement(el: CADElement, layer: CADLayer, style: LayerStyle): void {
+    this.rec('drawElement', [el, layer, style]);
+  }
+
+  removeElement(id: string): void {
+    this.rec('removeElement', [id]);
+  }
+
+  clearElements(): void {
+    this.rec('clearElements', []);
+  }
+
+  drawPreview(el: CADElement | null): void {
+    this.rec('drawPreview', [el]);
+  }
+
+  setSelection(sel: SelectionState): void {
+    this.rec('setSelection', [sel]);
+  }
+
+  setSnapPoints(pts: Array<{ x: number; y: number; type: string }>): void {
+    this.rec('setSnapPoints', [pts]);
+  }
+
+  overlay(draw: (g: OverlayPainter) => void): void {
+    const painter: OverlayPainter = {
+      line(a: Pt, b: Pt, color: string, width?: number) {},
+      rect(x: number, y: number, w: number, h: number, strokeColor: string) {},
+      circle(center: Pt, radius: number, strokeColor: string) {},
+      text(text: string, at: Pt, color: string, fontSize?: number) {},
+    };
+    draw(painter);
+    this.rec('overlay', [null]);
+  }
+
+  hitTest(world: Pt, tolerancePx: number): CADElement | null {
+    this.rec('hitTest', [world, tolerancePx]);
+    return this.nextHitTestResult;
+  }
+}

frontend/src/render/pixi/PixiRenderer.ts

@@ -0,0 +1,436 @@
+/**
+ * PixiRenderer – WebGL-Implementierung des RenderAdapter (Task C2).
+ *
+ * - PixiJS v8 wird LAZY per dynamischem import() geladen — ein Ausfall des
+ *   Pixi-Moduls (z.B. fehlendes WebGL im Headless-Browser) beeinflusst damit
+ *   NICHT den Modul-Import der App (kein weißer Screen).
+ * - async Application.init(); danach synchron nutzbar über waitForReady()
+ * - Inkrementell: gerenderte Container pro Element-ID gecacht;
+ *   removeElement/clearElements halten Cache und Szene konsistent
+ * - drawElement konsumiert die testbaren Shape-Primitives (elementDrawers)
+ */
+import type { Application, Container, Graphics, Text } from 'pixi.js';
+import type {
+  RenderAdapter,
+  Viewport,
+  GridConfig,
+  BackgroundDrawConfig,
+  RulerConfig,
+  LayerStyle,
+  OverlayPainter,
+  SelectionState,
+} from '../types';
+import type { CADElement, CADLayer } from '../../types/cad.types';
+import type { Pt } from '../../tools/modification/geometry';
+import { elementToPrimitives } from './elementDrawers';
+
+export class PixiRenderer implements RenderAdapter {
+  private app: Application | null = null;
+  private canvas: HTMLCanvasElement | null = null;
+  private root: Container | null = null;
+  private overlayLayer: Container | null = null;
+  private graphicsCache = new Map<string, Container>();
+  private viewport: Viewport = { x: 0, y: 0, scale: 1, width: 800, height: 600 };
+  private readyResolve: (() => void) | null = null;
+  private readyReject: ((err: unknown) => void) | null = null;
+  readonly ready: Promise<void>;
+  private pixiModule: typeof import('pixi.js') | null = null;
+
+  constructor() {
+    this.ready = new Promise<void>((resolve, reject) => {
+      this.readyResolve = resolve;
+      this.readyReject = reject;
+    });
+  }
+
+  /** Wartet auf Abschluss der Initialisierung; rejected bei Pixi-Fehler. */
+  async waitForReady(): Promise<void> {
+    await this.ready;
+  }
+
+  /** Task C4: true sobald setupApp fertig ist (via readyResolve gesetzt). */
+  private initialized = false;
+
+  // ── Lifecycle ────────────────────────────────────────────
+
+  init(canvas: HTMLCanvasElement): void {
+    this.canvas = canvas;
+    // LAZY-IMPORT: pixi.js wird erst jetzt geholt. Bei Fehler → ready rejected,
+    // CanvasArea deaktiviert das Overlay und die App läuft normal weiter.
+    void import('pixi.js')
+      .then((mod) => {
+        this.pixiModule = mod;
+        return this.setupApp(mod.Application, mod.Container, canvas);
+      })
+      .then(() => this.readyResolve?.())
+      .catch((err) => {
+        this.readyReject?.(err);
+      });
+  }
+
+  private setupApp(
+    ApplicationCtor: typeof Application,
+    ContainerCtor: typeof Container,
+    canvas: HTMLCanvasElement,
+  ): Promise<void> {
+    const app = new ApplicationCtor();
+    this.app = app;
+    return app.init({
+      canvas,
+      width: this.viewport.width,
+      height: this.viewport.height,
+      backgroundAlpha: 0,
+      antialias: true,
+      autoDensity: false,
+      preference: 'webgl',
+    }).then(() => {
+      if (!this.app) return;
+      const root = new ContainerCtor();
+      this.root = root;
+      this.app.stage.addChild(root);
+      const overlay = new ContainerCtor();
+      this.overlayLayer = overlay;
+      this.app.stage.addChild(overlay);
+      this.applyViewportTransform();
+      this.initialized = true;              // Task C4: fuer getDebugInfo
+    });
+  }
+
+  resize(width: number, height: number, _dpr: number): void {
+    if (!this.app?.renderer) return;
+    this.viewport.width = width;
+    this.viewport.height = height;
+    this.app.renderer.resize(width, height);
+  }
+
+  setViewport(vp: Viewport): void {
+    this.viewport = vp;
+    this.applyViewportTransform();
+  }
+
+  destroy(): void {
+    try {
+      this.app?.destroy(true, { children: true });
+    } catch {
+      // Pixi darf im Teardown nichts mehr werfen
+    }
+    this.app = null;
+    this.root = null;
+    this.overlayLayer = null;
+    this.graphicsCache.clear();
+    this.canvas = null;
+  }
+
+  // ── Basis-Zeichenoperationen ────────────────────────────
+
+  clear(_color: string): void {
+    // Hintergrund kommt vom Canvas-CSS; Pixi leert Buffer beim render.
+  }
+
+  drawGrid(cfg: GridConfig): void {
+    if (!cfg.enabled || !this.overlayLayer || !this.root) return;
+    const GraphicsCtor = this.pixiModule?.Graphics;
+    if (!GraphicsCtor) return;
+    const g = new GraphicsCtor();
+    const vp = this.viewport;
+    const worldLeft = vp.x;
+    const worldTop = vp.y;
+    const worldRight = vp.x + vp.width / vp.scale;
+    const worldBottom = vp.y + vp.height / vp.scale;
+    for (
+      let gx = Math.floor(worldLeft / cfg.size) * cfg.size;
+      gx < worldRight;
+      gx += cfg.size
+    ) {
+      g.moveTo(gx, worldTop).lineTo(gx, worldBottom)
+        .stroke({ color: cfg.color, width: 0.5 / vp.scale });
+    }
+    for (
+      let gy = Math.floor(worldTop / cfg.size) * cfg.size;
+      gy < worldBottom;
+      gy += cfg.size
+    ) {
+      g.moveTo(worldLeft, gy).lineTo(worldRight, gy)
+        .stroke({ color: cfg.color, width: 0.5 / vp.scale });
+    }
+    this.root.addChild(g);
+  }
+
+  drawBackground(_img: HTMLImageElement | null, _cfg: BackgroundDrawConfig): void {
+    // Sprite-/Texturintegration folgt in Task C3.
+  }
+
+  drawRuler(_cfg: RulerConfig): void {
+    // Lineal-Rendering folgt in Task C3.
+  }
+
+  // ── Elemente ─────────────────────────────────────────────
+
+  drawElement(el: CADElement, layer: CADLayer, _style: LayerStyle): void {
+    if (!this.root || !layer.visible || layer.locked) return;
+    this.removeElement(el.id);
+    const container = this.buildGraphicsContainer(el);
+    if (!container) return;
+    this.graphicsCache.set(el.id, container);
+    this.root.addChild(container);
+  }
+
+  removeElement(id: string): void {
+    const existing = this.graphicsCache.get(id);
+    if (!existing) return;
+    try {
+      existing.destroy({ children: true });
+    } catch {
+      // teardown-safe
+    }
+    this.graphicsCache.delete(id);
+  }
+
+  clearElements(): void {
+    for (const c of this.graphicsCache.values()) {
+      try {
+        c.destroy({ children: true });
+      } catch {
+        // teardown-safe
+      }
+    }
+    this.graphicsCache.clear();
+  }
+
+  drawPreview(el: CADElement | null): void {
+    if (!this.overlayLayer) return;
+    for (const child of [...this.overlayLayer.children]) {
+      if ((child as Container).label === '__preview__') {
+        try {
+          child.destroy({ children: true });
+        } catch {
+          // teardown-safe
+        }
+      }
+    }
+    if (!el) return;
+    const g = this.buildGraphicsContainer(el);
+    if (g) {
+      g.label = '__preview__';
+      g.alpha = 0.6;
+      this.overlayLayer.addChild(g);
+    }
+  }
+
+  setSelection(sel: SelectionState): void {
+    if (!this.overlayLayer) return;
+    // Bestehende Selektions-Grafik entfernen:
+    for (const child of [...this.overlayLayer.children]) {
+      if ((child as Container).label === '__selection__') {
+        try {
+          child.destroy({ children: true });
+        } catch {
+          // teardown-safe
+        }
+      }
+    }
+    if (!sel.selectedIds.length || !sel.elements || !this.pixiModule) return;
+
+    const GraphicsCtor = this.pixiModule.Graphics;
+    const g = new GraphicsCtor();
+    const HANDLE = 4; // halbe Kantenlänge der Eck-Handles (in Weltkoordinaten)
+
+    for (const el of sel.elements) {
+      if (!sel.selectedIds.includes(el.id)) continue;
+      // Legacy-Konvention getElementBBox: x/y = Zentrum für rects, sonst BBox
+      let minX: number, minY: number, maxX: number, maxY: number;
+      if (el.type === 'rect' || el.type === 'stage') {
+        minX = el.x - el.width / 2;
+        minY = el.y - el.height / 2;
+        maxX = el.x + el.width / 2;
+        maxY = el.y + el.height / 2;
+      } else if (
+        el.properties &&
+        el.properties.x1 !== undefined && el.properties.y1 !== undefined &&
+        el.properties.x2 !== undefined && el.properties.y2 !== undefined
+      ) {
+        minX = Math.min(el.properties.x1 as number, el.properties.x2 as number);
+        minY = Math.min(el.properties.y1 as number, el.properties.y2 as number);
+        maxX = Math.max(el.properties.x1 as number, el.properties.x2 as number);
+        maxY = Math.max(el.properties.y1 as number, el.properties.y2 as number);
+      } else {
+        minX = el.x - el.width / 2;
+        minY = el.y - el.height / 2;
+        maxX = el.x + el.width / 2;
+        maxY = el.y + el.height / 2;
+      }
+
+      // Umrandung (gestrichelt wird via Linien-Segmenten simuliert):
+      const dashLen = 6;
+      const drawDashed = (ax: number, ay: number, bx: number, by: number) => {
+        const len = Math.hypot(bx - ax, by - ay);
+        const n = Math.max(1, Math.floor(len / dashLen));
+        for (let i = 0; i <= n; i += 2) {
+          const t0 = i / n;
+          const t1 = Math.min(1, (i + 1) / n);
+          g.moveTo(ax + (bx - ax) * t0, ay + (by - ay) * t0)
+            .lineTo(ax + (bx - ax) * t1, ay + (by - ay) * t1)
+            .stroke({ color: '#50fa7b', width: 1 / this.viewport.scale });
+        }
+      };
+      drawDashed(minX, minY, maxX, minY);
+      drawDashed(maxX, minY, maxX, maxY);
+      drawDashed(maxX, maxY, minX, maxY);
+      drawDashed(minX, maxY, minX, minY);
+
+      // 4 Eck-Handles (gefüllte Quadrate):
+      const corners = [
+        { x: minX, y: minY }, { x: maxX, y: minY },
+        { x: maxX, y: maxY }, { x: minX, y: maxY },
+      ];
+      for (const c of corners) {
+        g.rect(c.x - HANDLE, c.y - HANDLE, HANDLE * 2, HANDLE * 2)
+          .fill({ color: '#50fa7b' })
+          .stroke({ color: '#1e1e2e', width: 1 / this.viewport.scale });
+      }
+    }
+    g.label = '__selection__';
+    this.overlayLayer.addChild(g);
+  }
+
+  setSnapPoints(pts: Array<{ x: number; y: number; type: string }>): void {
+    if (!this.overlayLayer || !this.pixiModule || pts.length === 0) return;
+    const GraphicsCtor = this.pixiModule.Graphics;
+    const g = new GraphicsCtor();
+    g.label = '__snaps__';
+    // Bestehende Snap-Marks entfernen:
+    for (const child of [...this.overlayLayer.children]) {
+      if ((child as Container).label === '__snaps__') {
+        try {
+          child.destroy({ children: true });
+        } catch {
+          // teardown-safe
+        }
+      }
+    }
+    // Snap-Punkt farbig nach Typ (Legacy-Ähnlich):
+    const colorByType: Record<string, string> = {
+      endpoint: '#ff79c6',
+      midpoint: '#8be9fd',
+      center: '#f1fa8c',
+      intersection: '#ffb86c',
+      grid: '#6272a4',
+    };
+    const scaleComp = 1 / this.viewport.scale; // konstante Bildschirmgröße
+    for (const pt of pts) {
+      const color = colorByType[pt.type] ?? '#bd93f9';
+      g.circle(pt.x, pt.y, 4 * scaleComp)
+        .fill({ color })
+        .stroke({ color: '#1e1e2e', width: 1 * scaleComp });
+    }
+    this.overlayLayer.addChild(g);
+  }
+
+  overlay(draw: (g: OverlayPainter) => void): void {
+    if (!this.overlayLayer) return;
+    const GraphicsCtor = this.pixiModule?.Graphics;
+    const TextCtor = this.pixiModule?.Text;
+    if (!GraphicsCtor || !TextCtor) return;
+    const g = new GraphicsCtor();
+    const painter: OverlayPainter = {
+      line: (a: Pt, b: Pt, color: string, width?: number) => {
+        g.moveTo(a.x, a.y).lineTo(b.x, b.y).stroke({ color, width: width ?? 1 });
+      },
+      rect: (x: number, y: number, w: number, h: number, strokeColor: string) => {
+        g.rect(x, y, w, h).stroke({ color: strokeColor });
+      },
+      circle: (center: Pt, radius: number, strokeColor: string) => {
+        g.circle(center.x, center.y, radius).stroke({ color: strokeColor });
+      },
+      text: (text: string, at: Pt, color: string, fontSize?: number) => {
+        const t = new TextCtor({ text, style: { fontSize: fontSize ?? 12, fill: color } });
+        t.position.set(at.x, at.y);
+        g.addChild(t);
+      },
+    };
+    draw(painter);
+    this.overlayLayer.addChild(g);
+  }
+
+  hitTest(_world: Pt, _tolerancePx: number): CADElement | null {
+    // Delegation an SpatialIndex folgt in C3.
+    return null;
+  }
+
+  /**
+   * Task C4: Debug-Info für Playwright-E2E-Assertions.
+   * Ermöglicht Testabfragen wie 'wie viele Elemente sind gerendert?'
+   */
+  getDebugInfo(): { cachedElements: number; ready: boolean } {
+    return {
+      cachedElements: this.graphicsCache.size,
+      ready: this.initialized,
+    };
+  }
+
+  // ── Internes ─────────────────────────────────────────────
+
+  private applyViewportTransform(): void {
+    if (!this.root) return;
+    this.root.position.set(
+      -this.viewport.x * this.viewport.scale,
+      -this.viewport.y * this.viewport.scale,
+    );
+    this.root.scale.set(this.viewport.scale);
+  }
+
+  private buildGraphicsContainer(el: CADElement): Container | null {
+    const prims = elementToPrimitives(el);
+    if (prims.length === 0) return null;
+    const GraphicsCtor = this.pixiModule?.Graphics;
+    const TextCtor = this.pixiModule?.Text;
+    if (!GraphicsCtor || !TextCtor) return null;
+    const ContainerCtor = this.pixiModule!.Container;
+    const container = new ContainerCtor();
+    for (const prim of prims) {
+      const g = new GraphicsCtor();
+      switch (prim.kind) {
+        case 'line':
+          g.moveTo(prim.from.x, prim.from.y)
+            .lineTo(prim.to.x, prim.to.y)
+            .stroke({ color: prim.stroke, width: prim.strokeWidth });
+          break;
+        case 'rect':
+          g.rect(prim.x, prim.y, prim.w, prim.h);
+          if (prim.fill) g.fill({ color: prim.fill });
+          g.stroke({ color: prim.stroke, width: prim.strokeWidth });
+          break;
+        case 'circle':
+          g.circle(prim.center.x, prim.center.y, prim.radius);
+          if (prim.fill) g.fill({ color: prim.fill });
+          g.stroke({ color: prim.stroke, width: prim.strokeWidth });
+          break;
+        case 'polyline': {
+          if (prim.points.length === 0) break;
+          g.moveTo(prim.points[0].x, prim.points[0].y);
+          for (let i = 1; i < prim.points.length; i++) {
+            g.lineTo(prim.points[i].x, prim.points[i].y);
+          }
+          if (prim.close) g.closePath();
+          g.stroke({ color: prim.stroke, width: prim.strokeWidth });
+          break;
+        }
+        case 'arc': {
+          const startRad = (prim.startDeg * Math.PI) / 180;
+          const endRad = (prim.endDeg * Math.PI) / 180;
+          g.arc(prim.center.x, prim.center.y, prim.radius, startRad, endRad)
+            .stroke({ color: prim.stroke, width: prim.strokeWidth });
+          break;
+        }
+        case 'text': {
+          const t = new TextCtor({ text: prim.text, style: { fontSize: prim.fontSize, fill: prim.color } });
+          t.position.set(prim.at.x, prim.at.y);
+          g.addChild(t);
+          break;
+        }
+      }
+      container.addChild(g);
+    }
+    return container;
+  }
+}

frontend/src/render/pixi/elementDrawers.ts

@@ -0,0 +1,324 @@
+/**
+ * elementDrawers – Reine Beschreibungs-Fabrik (Task C2).
+ *
+ * Wandelt CADElemente in eine Liste von Primitiven um (line/rect/circle/
+ * polyline/text/arc). Der PixiRenderer (C3) konsumiert diese Deskriptoren
+ * und überführt sie in konkrete Grafikobjekte.
+ *
+ * Vorteil dieser Zwischenschicht:
+ * - Vollständig unit-testbar OHNE WebGL/GPU
+ * - Backend-unabhängig (Pixi jetzt, Canvas2D oder andere später)
+ *
+ * Konventionen entsprechen dem Legacy RenderEngine.draw*:
+ * - rect: x/y = Zentrum der BBox
+ * - circle/arc: radius über properties.radius (Fallback width/2)
+ * - arc-Winkel in Grad, 0° = 3 Uhr, gegen den Uhrzeigersinn
+ */
+import type { CADElement } from '../../types/cad.types';
+import type { Pt } from '../../tools/modification/geometry';
+
+/** Zeichenprimitiv — kleinste darstellbare Einheit. */
+export type ShapePrimitive =
+  | { kind: 'line'; from: Pt; to: Pt; stroke: string; strokeWidth: number }
+  | { kind: 'rect'; x: number; y: number; w: number; h: number; fill: string | null; stroke: string; strokeWidth: number }
+  | { kind: 'circle'; center: Pt; radius: number; fill: string | null; stroke: string; strokeWidth: number }
+  | { kind: 'polyline'; points: Pt[]; close: boolean; stroke: string; strokeWidth: number }
+  | { kind: 'text'; at: Pt; text: string; fontSize: number; color: string }
+  | { kind: 'arc'; center: Pt; radius: number; startDeg: number; endDeg: number; stroke: string; strokeWidth: number };
+
+const FALLBACK_STROKE = '#e0e0e0';
+
+function asPoint(p: unknown): Pt {
+  const q = p as { x?: number; y?: number };
+  return { x: Number(q?.x ?? 0), y: Number(q?.y ?? 0) };
+}
+
+function fillOrNull(raw: unknown): string | null {
+  return typeof raw === 'string' && raw !== 'none' ? raw : null;
+}
+
+/**
+ * Wandelt ein CADElement in seine Zeichenprimitive um.
+ * Gibt ein leeres Array zurück für unbekannte Typen bzw. Elemente,
+ * die nichts Sichtbares beitragen (z.B. leerer Text).
+ */
+export function elementToPrimitives(el: CADElement, attrDefs?: Array<{ tag: string; prompt: string; defaultValue?: string }>): ShapePrimitive[] {
+  const props = (el.properties ?? {}) as Record<string, unknown>;
+  const stroke = (props.stroke as string | undefined) ?? FALLBACK_STROKE;
+  const sw = (props.strokeWidth as number | undefined) ?? 1;
+
+  switch (el.type) {
+    case 'line': {
+      if (
+        props.x1 === undefined || props.y1 === undefined ||
+        props.x2 === undefined || props.y2 === undefined
+      ) {
+        return [];
+      }
+      return [{
+        kind: 'line',
+        from: { x: props.x1 as number, y: props.y1 as number },
+        to: { x: props.x2 as number, y: props.y2 as number },
+        stroke,
+        strokeWidth: sw,
+      }];
+    }
+
+    case 'rect': {
+      // Legacy-BBox-Konvention: x/y ist das Zentrum des Rechtecks
+      return [{
+        kind: 'rect',
+        x: el.x - el.width / 2,
+        y: el.y - el.height / 2,
+        w: el.width,
+        h: el.height,
+        fill: fillOrNull(props.fill),
+        stroke,
+        strokeWidth: sw,
+      }];
+    }
+
+    case 'circle': {
+      const radius = (props.radius as number | undefined) ?? el.width / 2;
+      return [{
+        kind: 'circle',
+        center: { x: el.x, y: el.y },
+        radius,
+        fill: fillOrNull(props.fill),
+        stroke,
+        strokeWidth: sw,
+      }];
+    }
+
+    case 'arc': {
+      const radius = (props.radius as number | undefined) ?? el.width / 2;
+      return [{
+        kind: 'arc',
+        center: { x: el.x, y: el.y },
+        radius,
+        startDeg: (props.startAngle as number | undefined) ?? 0,
+        endDeg: (props.endAngle as number | undefined) ?? 360,
+        stroke,
+        strokeWidth: sw,
+      }];
+    }
+
+    case 'polyline':
+    case 'polygon': {
+      const pts = Array.isArray(props.points)
+        ? (props.points as unknown[]).map(asPoint)
+        : [];
+      if (pts.length < 2) return [];
+      return [{
+        kind: 'polyline',
+        points: pts,
+        close: el.type === 'polygon',
+        stroke,
+        strokeWidth: sw,
+      }];
+    }
+
+    case 'text': {
+      const txt = String(props.text ?? '');
+      if (!txt) return []; // leeren Platzhalter nicht rendern
+      return [{
+        kind: 'text',
+        at: { x: el.x, y: el.y },
+        text: txt,
+        fontSize: (props.fontSize as number | undefined) ?? 12,
+        color: (props.color as string | undefined) ?? stroke,
+      }];
+    }
+
+    // ── Task C3: bisher im Pixi-Pfad fehlende Typen ──
+
+    case 'dimension': {
+      // Legacy-Konvention: x1..y2 in properties, BBox-Zentrum als x/y,
+      // Extension lines + Hauptlinie; Pfeilspitzen sind Detail (C3+)
+      const x1 = (props.x1 as number | undefined) ?? el.x - el.width / 2;
+      const y1 = (props.y1 as number | undefined) ?? el.y;
+      const x2 = (props.x2 as number | undefined) ?? el.x + el.width / 2;
+      const y2 = (props.y2 as number | undefined) ?? el.y;
+      const color = (props.color as string | undefined) ?? '#aaaaaa';
+      const dimColor = (props.dimColor as string | undefined) ?? color;
+      const label = String(props.value ?? props.text ?? '');
+      const out: ShapePrimitive[] = [
+        { kind: 'line', from: { x: x1, y: y1 }, to: { x: x2, y: y2 }, stroke: dimColor, strokeWidth: 1 },
+      ];
+      if (label) {
+        out.push({
+          kind: 'text',
+          at: { x: (x1 + x2) / 2, y: (y1 + y2) / 2 - 12 },
+          text: label,
+          fontSize: 10,
+          color: dimColor,
+        });
+      }
+      return out;
+    }
+
+    case 'leader': {
+      // Legacy-Konvention: Linie p1→p2 + optionaler Text am Ende
+      const lx1 = (props.x1 as number | undefined) ?? el.x;
+      const ly1 = (props.y1 as number | undefined) ?? el.y;
+      const lx2 = (props.x2 as number | undefined) ?? el.x + el.width;
+      const ly2 = (props.y2 as number | undefined) ?? el.y + el.height;
+      const out: ShapePrimitive[] = [
+        { kind: 'line', from: { x: lx1, y: ly1 }, to: { x: lx2, y: ly2 }, stroke, strokeWidth: sw },
+      ];
+      const label = String(props.text ?? '');
+      if (label) {
+        out.push({
+          kind: 'text',
+          at: { x: lx2 + 4, y: ly2 - 4 },
+          text: label,
+          fontSize: (props.fontSize as number | undefined) ?? 12,
+          color: stroke,
+        });
+      }
+      return out;
+    }
+
+    case 'revcloud': {
+      // Revisionswolke: Punkte-Zug (Bogen-Detail folgt in C3+)
+      const pts = Array.isArray(props.points)
+        ? (props.points as unknown[]).map(asPoint)
+        : [];
+      if (pts.length < 2) return [];
+      return [{
+        kind: 'polyline',
+        points: pts,
+        close: true,
+        stroke,
+        strokeWidth: sw,
+      }];
+    }
+
+    case 'chair': {
+      // Stuhl: gefülltes Quadrat in Element-Farbe + Umrandung
+      const fill = (props.fill as string | undefined) ?? '#4a90d9';
+      return [{
+        kind: 'rect',
+        x: el.x - el.width / 2,
+        y: el.y - el.height / 2,
+        w: el.width,
+        h: el.height,
+        fill,
+        stroke: (props.outlineColor as string | undefined) ?? '#2a5a99',
+        strokeWidth: 1,
+      }];
+    }
+
+    case 'table': {
+      // Tisch: Kreis in Element-Größe mit Füllung
+      const fill = (props.fill as string | undefined) ?? '#8b7355';
+      return [{
+        kind: 'circle',
+        center: { x: el.x, y: el.y },
+        radius: Math.max(el.width, el.height) / 2,
+        fill,
+        stroke: '#5a4a35',
+        strokeWidth: 1,
+      }];
+    }
+
+    case 'stage': {
+      // Bühne: Rechteck mit dunkler Füllung
+      return [{
+        kind: 'rect',
+        x: el.x - el.width / 2,
+        y: el.y - el.height / 2,
+        w: el.width,
+        h: el.height,
+        fill: (props.fill as string | undefined) ?? '#3a3a4a',
+        stroke,
+        strokeWidth: 1.5,
+      }];
+    }
+
+    case 'curtain': {
+      // Vorhang (Task E7): wellige Polyline entlang der Breite.
+      const pts = Array.isArray(props.points)
+        ? (props.points as unknown[]).map(asPoint)
+        : [];
+      if (pts.length >= 2) {
+        return [{ kind: 'polyline', points: pts, close: false, stroke, strokeWidth: sw }];
+      }
+      return [{
+        kind: 'line',
+        from: { x: el.x - el.width / 2, y: el.y },
+        to: { x: el.x + el.width / 2, y: el.y },
+        stroke,
+        strokeWidth: sw,
+      }];
+    }
+
+    case 'spotlight': {
+      // Scheinwerfer (Task E7): Kegel-Polygon in properties.color.
+      const pts = Array.isArray(props.points)
+        ? (props.points as unknown[]).map(asPoint)
+        : [];
+      if (pts.length >= 3) {
+        const col = (props.color as string | undefined) ?? '#ffcc00';
+        return [{ kind: 'polyline', points: pts, close: true, stroke: col, strokeWidth: sw }];
+      }
+      return [];
+    }
+
+    case 'barrier': {
+      // Absperrung (Task E7): Kette aus Kreis-Paaren (properties.circles).
+      const circles = Array.isArray(props.circles)
+        ? (props.circles as Array<{ x: number; y: number; r: number }>)
+        : [];
+      const col = (props.color as string | undefined) ?? '#c0392b';
+      if (circles.length > 0) {
+        return circles.map((c) => ({
+          kind: 'circle' as const,
+          center: { x: c.x, y: c.y },
+          radius: c.r,
+          fill: null,
+          stroke: col,
+          strokeWidth: 1,
+        }));
+      }
+      const out: ShapePrimitive[] = [];
+      const N = 5;
+      for (let i = 0; i < N; i++) {
+        out.push({
+          kind: 'circle',
+          center: { x: el.x - el.width / 2 + (el.width * (i + 0.5)) / N, y: el.y },
+          radius: Math.min(6, el.width / (N * 2.5)),
+          fill: null,
+          stroke: col,
+          strokeWidth: 1,
+        });
+      }
+      return out;
+    }
+
+    case 'block_instance': {
+      // Task D12: Attr-Texte der Instanz zeichnen (tag=Wert, default-Fallback).
+      const attrValues = (props.attrValues as Record<string, string> | undefined) ?? {};
+      if (!attrDefs || attrDefs.length === 0) return [];
+      const out: ShapePrimitive[] = [];
+      const fontSize = 9;
+      const lineH = 16;
+      let i = 0;
+      for (const def of attrDefs) {
+        const value = attrValues[def.tag] ?? def.defaultValue ?? '—';
+        out.push({
+          kind: 'text',
+          at: { x: el.x, y: el.y - 8 - i * lineH },
+          text: `${def.tag}=${value}`,
+          fontSize,
+          color: stroke,
+        });
+        i++;
+      }
+      return out;
+    }
+
+    default:
+      return [];
+  }
+}

frontend/src/render/types.ts

@@ -0,0 +1,123 @@
+/**
+ * render/types.ts – RenderAdapter-Schnittstelle (Task C1).
+ *
+ * Ziel-Architektur: ALLES Rendering läuft gegen diese schmale API.
+ * Implementierungen:
+ *   - render/pixi/PixiRenderer.ts (WebGL, Task C2+)
+ *   - tests/helpers/mockAdapter.ts (Headless-Recorder für Unit-Tests)
+ *
+ * Phase D/E-Erweiterungen (Plugins, Custom-Elemente) nutzen denselben Vertrag
+ * über drawOverlay/drawCustom.
+ */
+import type { CADElement, CADLayer } from '../types/cad.types';
+import type { Pt } from '../tools/modification/geometry';
+
+/** Aktueller Ausschnitt in Weltkoordinaten + Skalierung. */
+export interface Viewport {
+  x: number;
+  y: number;
+  scale: number;
+  width: number;
+  height: number;
+}
+
+/** Zeichenraster-Konfiguration. */
+export interface GridConfig {
+  enabled: boolean;
+  size: number;
+  color: string;
+}
+
+/** Hintergrundbild-Konfiguration (Spiegelung der Legacy RenderOptions-Felder). */
+export interface BackgroundDrawConfig {
+  src?: string;
+  opacity?: number;
+  offsetX?: number;
+  offsetY?: number;
+  scale?: number;
+  rotation?: number;
+}
+
+/** Lineal-Konfiguration. */
+export interface RulerConfig {
+  enabled: boolean;
+  unit: string;
+  scaleFactor: number;
+}
+
+/** Stil pro CAD-Layer (Farbe/Linientyp/Transparenz). */
+export interface LayerStyle {
+  color: string;
+  lineType: string;
+  transparency: number;
+  visible: boolean;
+}
+
+/** Freihand-Zeichner für temporäre Overlays (Marquee, Tool-Hilfslinien). */
+export interface OverlayPainter {
+  line(a: Pt, b: Pt, color: string, width?: number): void;
+  rect(x: number, y: number, w: number, h: number, strokeColor: string): void;
+  circle(center: Pt, radius: number, strokeColor: string): void;
+  text(text: string, at: Pt, color: string, fontSize?: number): void;
+}
+
+/** Selektionszustand für die Anzeige von Handles. */
+export interface SelectionState {
+  selectedIds: string[];
+  /** Task C3-Finish: Elemente für Handle-Zeichnung (Renderer braucht BBox). */
+  elements?: CADElement[];
+}
+
+/**
+ * Der zentrale Rendervertrag. Implementierungen MÜSSEN alle Methoden bereitstellen,
+ * auch wenn einzelne initial No-Ops sind (z.B. drawBackground ohne Bild).
+ */
+export interface RenderAdapter {
+  /** Bindet den Renderer an ein Canvas-Element (einmalig). */
+  init(canvas: HTMLCanvasElement): void;
+
+  /** Reaktion auf Größenänderungen (DPR-bewusst). */
+  resize(width: number, height: number, dpr: number): void;
+
+  /** Setzt den aktuellen Ausschnitt; danach ist ein neuer Frame nötig. */
+  setViewport(vp: Viewport): void;
+
+  /// Gibt WebGL-/DOM-Ressourcen frei. */
+  destroy(): void;
+
+  /** Leert die Zeichenfläche mit einer Grundfarbe. */
+  clear(color: string): void;
+
+  /** Zeichnet das Raster. */
+  drawGrid(cfg: GridConfig): void;
+
+  /** Zeichnet das Hintergrundbild, falls konfiguriert. */
+  drawBackground(img: HTMLImageElement | null, cfg: BackgroundDrawConfig): void;
+
+  /** Zeichnet das Lineal. */
+  drawRuler(cfg: RulerConfig): void;
+
+  /** Zeichnet ein Element im Kontext seines Layers (Stil, Sichtbarkeit). */
+  drawElement(el: CADElement, layer: CADLayer, style: LayerStyle): void;
+
+  /** Entfernt ein Element aus dem Rendering (z.B. nach Löschen in Yjs). */
+  removeElement(id: string): void;
+
+  /** Entfernt ALLE gerenderten Elemente (Reset bei Dokumentwechsel). */
+  clearElements(): void;
+
+  /** Zeichnet ein Element in Transformation / Live-Vorschau. */
+  drawPreview(el: CADElement | null): void;
+
+  /** Synchronisiert die Selektionsanzeige (Handles, Umrandungen). */
+  setSelection(sel: SelectionState): void;
+
+  /** Snap-Markierungen setzen/entfernen. */
+  setSnapPoints(pts: Array<{ x: number; y: number; type: string }>): void;
+
+  /** Öffnet einen Overlay-Pass für freihand-Overlays (Tools). */
+  overlay(draw: (g: OverlayPainter) => void): void;
+
+  /** Treffer abfragen (Delegation an SpatialIndex; kein GPU-Picking). */
+  hitTest(world: Pt, tolerancePx: number): CADElement | null;
+}

frontend/src/services/api.ts

@@ -660,6 +660,7 @@ export interface GlobalBlock {
   name: string;
   block_data: string;
   svg_data: string | null;
+  is_favorite: boolean;
   created_at: string;
   updated_at: string;
 }
@@ -698,6 +699,17 @@ export async function renameGlobalBlock(token: string, id: string, name: string)
   return res.json();
 }
 
+// Task F2: Favorite-Toggle für globale Blöcke
+export async function setGlobalBlockFavorite(token: string, id: string, isFavorite: boolean): Promise<GlobalBlock> {
+  const res = await fetch(`${API_BASE}/api/global-blocks/${id}`, {
+    method: 'PATCH',
+    headers: authHeaders(token),
+    body: JSON.stringify({ is_favorite: isFavorite }),
+  });
+  if (!res.ok) throw new Error('Failed to set favorite');
+  return res.json();
+}
+
 export async function deleteGlobalBlock(token: string, id: string): Promise<void> {
   const res = await fetch(`${API_BASE}/api/global-blocks/${id}`, {
     method: 'DELETE',
@@ -764,3 +776,106 @@ export async function aiChat(
   }
   return res.json();
 }
+
+// ─── Guests (Task E6) ──────────────────────────────────
+export interface Guest {
+  id: string;
+  drawing_id: string;
+  name: string;
+  email?: string | null;
+  category: string;
+  seat_element_id?: string | null;
+  notes?: string | null;
+  created_at: string;
+}
+
+export async function listGuests(token: string, drawingId: string): Promise<Guest[]> {
+  const res = await fetch(`${API_BASE}/api/drawings/${drawingId}/guests`, {
+    headers: authHeaders(token),
+  });
+  if (!res.ok) throw new Error(`Failed to list guests: ${res.status}`);
+  return res.json();
+}
+
+export async function createGuest(token: string, drawingId: string, data: { name: string; email?: string; category?: string; notes?: string }): Promise<Guest> {
+  const res = await fetch(`${API_BASE}/api/drawings/${drawingId}/guests`, {
+    method: 'POST',
+    headers: authHeaders(token),
+    body: JSON.stringify(data),
+  });
+  if (!res.ok) throw new Error(`Failed to create guest: ${res.status}`);
+  return res.json();
+}
+
+export async function updateGuest(token: string, id: string, data: Partial<{ name: string; email: string; category: string; seat_element_id: string; notes: string }>): Promise<Guest> {
+  const res = await fetch(`${API_BASE}/api/guests/${id}`, {
+    method: 'PATCH',
+    headers: authHeaders(token),
+    body: JSON.stringify(data),
+  });
+  if (!res.ok) throw new Error(`Failed to update guest: ${res.status}`);
+  return res.json();
+}
+
+export async function deleteGuest(token: string, id: string): Promise<void> {
+  const res = await fetch(`${API_BASE}/api/guests/${id}`, {
+    method: 'DELETE',
+    headers: authHeaders(token),
+  });
+  if (!res.ok) throw new Error(`Failed to delete guest: ${res.status}`);
+}
+
+// ─── Library Paket Export/Import (Task F1) ─────────────
+export interface WcadlibPackage {
+  format: 'wcadlib';
+  version: number;
+  exported_at?: string;
+  folders: Array<{ id: string; name: string; parent_id: string | null }>;
+  blocks: Array<{ name: string; folder_id: string | null; block_data: string; svg_data: string | null }>;
+}
+
+export async function exportLibrary(token: string): Promise<unknown> {
+  const res = await fetch(`${API_BASE}/api/global-blocks/export`, {
+    headers: authHeaders(token),
+  });
+  if (!res.ok) throw new Error(`Failed to export library: ${res.status}`);
+  return res.json();
+}
+
+export async function importLibrary(token: string, pkg: { format: string; version?: number; folders?: Array<{ id: string; name: string; parent_id: string | null }>; blocks: Array<{ name: string; folder_id: string | null; block_data: string; svg_data: string | null }> }): Promise<{ imported_blocks: number; imported_folders: number }> {
+  const res = await fetch(`${API_BASE}/api/global-blocks/import`, {
+    method: 'POST',
+    headers: authHeaders(token),
+    body: JSON.stringify(pkg),
+  });
+  if (!res.ok) {
+    const err = await res.text();
+    throw new Error(`Failed to import library: ${res.status} ${err}`);
+  }
+  return res.json();
+}
+
+// ─── Task F7: .wcadlib als echtes ZIP-Paket ──────────────
+
+/** Library als ZIP-Paket (manifest.json, blocks.json, thumbs/) herunterladen. */
+export async function exportLibraryZip(token: string): Promise<Blob> {
+  const res = await fetch(`${API_BASE}/api/global-blocks/export-zip`, {
+    headers: authHeaders(token),
+  });
+  if (!res.ok) throw new Error(`Failed to export library zip: ${res.status}`);
+  return res.blob();
+}
+
+/** .wcadlib-ZIP einspielen (Ordner-Mapping, Blöcke, Thumbnails). */
+export async function importLibraryZip(token: string, file: Blob): Promise<{ imported_blocks: number; imported_folders: number }> {
+  const res = await fetch(`${API_BASE}/api/global-blocks/import-zip`, {
+    method: 'POST',
+    headers: { ...authHeaders(token), 'content-type': 'application/zip' },
+    body: file,
+  });
+  if (!res.ok) {
+    const err = await res.text();
+    throw new Error(`Failed to import library zip: ${res.status} ${err}`);
+  }
+  return res.json();
+}

frontend/src/services/dxfParser.ts

@@ -1,27 +1,53 @@
 /**
  * DXF Parser – converts DXF entities to CADElement[]
- * Uses dxf-parser library
+ * Uses dxf-parser library.
+ *
+ * Task F5 erweitert die Entity-Abdeckung: ELLIPSE (Polyline-Approx), SPLINE
+ * (Grad<=3 → de-Boor-Approx), MTEXT (Formatcode-Cleanup), POINT, ATTDEF und
+ * INSERT mit MINSERT-Arrays. HATCH wird defensiv mapping-fähig gehalten
+ * (dxf-parser 1.1.x schickt echte HATCH-Entities noch nicht durch).
+ *
+ * Neben `warnings` liefert parseDXF einen strukturierten Fehlerreport
+ * (`skippedEntities`: type + reason je übersprungener Entity).
  */
 import DxfParser from 'dxf-parser';
 import type { CADElement, CADLayer, CADProperties, ElementType } from '../types/cad.types';
 
+export interface SkippedEntity {
+  type: string;
+  reason: string;
+}
+
 export interface DXFImportResult {
   elements: CADElement[];
   layers: CADLayer[];
   warnings: string[];
+  skippedEntities: SkippedEntity[];
 }
 
 let idCounter = 0;
 const nextId = () => `dxf-${Date.now()}-${idCounter++}`;
 
+interface Pt { x: number; y: number }
+
+function bboxOf(pts: Pt[]): { x: number; y: number; width: number; height: number } {
+  const minX = Math.min(...pts.map((p) => p.x));
+  const minY = Math.min(...pts.map((p) => p.y));
+  const maxX = Math.max(...pts.map((p) => p.x));
+  const maxY = Math.max(...pts.map((p) => p.y));
+  return { x: minX, y: minY, width: maxX - minX, height: maxY - minY };
+}
+
 /**
  * Parse a DXF string into CAD elements and layers.
  */
 export function parseDXF(dxfString: string): DXFImportResult {
   const parser = new DxfParser();
   const dxf = parser.parseSync(dxfString) as any;
-  if (!dxf) return { elements: [], layers: [], warnings: ['DXF parse returned null'] };
+  const empty: DXFImportResult = { elements: [], layers: [], warnings: [], skippedEntities: [] };
+  if (!dxf) return { ...empty, warnings: ['DXF parse returned null'] };
   const warnings: string[] = [];
+  const skippedEntities: SkippedEntity[] = [];
   const layerMap = new Map<string, CADLayer>();
   const elements: CADElement[] = [];
 
@@ -52,22 +78,180 @@ export function parseDXF(dxfString: string): DXFImportResult {
     });
   }
 
-  // Parse entities
+  // Parse entities (INSERT expanded for MINSERT arrays)
   if (dxf.entities) {
     for (const entity of dxf.entities) {
+      if (entity?.type === 'INSERT') {
+        elements.push(...expandInsert(entity, layerMap));
+        continue;
+      }
       const el = entityToCADElement(entity, layerMap);
       if (el) {
         elements.push(el);
       } else {
-        warnings.push(`Unsupported entity type: ${entity.type}`);
+        const type = String(entity?.type ?? 'UNKNOWN');
+        const reason = skipReason(entity);
+        skippedEntities.push({ type, reason });
+        warnings.push(`Unsupported entity type: ${type} — ${reason}`);
       }
     }
   }
 
-  return { elements, layers: Array.from(layerMap.values()), warnings };
+  return { elements, layers: Array.from(layerMap.values()), warnings, skippedEntities };
 }
 
-function entityToCADElement(
+/** Grund, warum eine Entity übersprungen wurde (für den Fehlerreport). */
+export function skipReason(entity: any): string {
+  switch (entity?.type) {
+    case 'ELLIPSE':
+      return 'Ellipse ohne center/majorAxisEndPoint nicht darstellbar';
+    case 'SPLINE':
+      if ((entity?.degreeOfSplineCurve ?? 0) > 3) return 'Spline-Grad > 3 (Approx limitiert auf Grad <= 3)';
+      return 'Spline ohne verwertbare Kontrollpunkte';
+    case 'LINE':
+      return 'Line unvollständig (Start-/Endpunkt fehlt)';
+    case 'HATCH':
+      return 'HATCH-Grenzen nicht lesbar';
+    case 'ATTDEF':
+      return 'ATTDEF ohne tag';
+    default:
+      return 'Nicht unterstützter Entity-Typ';
+  }
+}
+
+/**
+ * INSERT → block_instance(s). MINSERT-Arrays (columnCount/rowCount > 1)
+ * erzeugen n-fache Instanzen mit Spacing-Offset.
+ */
+export function expandInsert(entity: any, layerMap?: Map<string, CADLayer>): CADElement[] {
+  const layerName = entity.layer || '0';
+  const layer = layerMap?.get(layerName) ?? layerMap?.get('0');
+  const layerId = layer?.id ?? `dxf-layer-${layerName}`;
+  const pos = entity.position;
+  if (!pos) return [];
+  const baseProps: CADProperties = {
+    stroke: entity.color ? (dxfColorToHex(entity.color) ?? layer?.color) : (layer?.color ?? '#ffffff'),
+    strokeWidth: 1,
+    blockId: entity.name,
+    scale: entity.scale || entity.xScale || 1,
+    scaleX: entity.xScale ?? 1,
+    scaleY: entity.yScale ?? 1,
+    rotation: entity.rotation || 0,
+  };
+  const cols = Math.max(1, Math.floor(entity.columnCount || 1));
+  const rows = Math.max(1, Math.floor(entity.rowCount || 1));
+  const colSpacing = entity.columnSpacing || 0;
+  const rowSpacing = entity.rowSpacing || 0;
+  const out: CADElement[] = [];
+  for (let r = 0; r < rows; r++) {
+    for (let c = 0; c < cols; c++) {
+      out.push({
+        id: nextId(), type: 'block_instance', layerId,
+        x: pos.x + c * colSpacing, y: pos.y + r * rowSpacing,
+        width: 0, height: 0,
+        properties: { ...baseProps },
+      });
+    }
+  }
+  return out;
+}
+
+/** ELLIPSE → Polyline-Approximation (64 Segmente bei Voll-Ellipse). */
+function ellipseToPoints(entity: any): Pt[] | null {
+  const c = entity.center;
+  const major = entity.majorAxisEndPoint;
+  if (!c || !major) return null;
+  const a = Math.hypot(major.x ?? 0, major.y ?? 0);
+  if (!(a > 0)) return null;
+  const ratio = typeof entity.axisRatio === 'number' && entity.axisRatio > 0 ? entity.axisRatio : 1;
+  const b = a * ratio;
+  const phi = Math.atan2(major.y ?? 0, major.x ?? 0);
+  const cosP = Math.cos(phi), sinP = Math.sin(phi);
+  const FULL = Math.PI * 2;
+  let start = typeof entity.startAngle === 'number' ? entity.startAngle : 0;
+  let end = typeof entity.endAngle === 'number' ? entity.endAngle : start + FULL;
+  let span = end - start;
+  const closed = !(span > 0.000001) || Math.abs(span - FULL) < 1e-6;
+  if (span <= 0) { start = 0; span = FULL; }
+  const n = Math.max(2, Math.round(64 * (span / FULL)));
+  const pts: Pt[] = [];
+  for (let i = 0; i < n; i++) {
+    const t = closed ? start + (i * span) / n : start + (i * span) / (n - 1);
+    const ct = Math.cos(t), st = Math.sin(t);
+    pts.push({
+      x: c.x + a * ct * cosP - b * st * sinP,
+      y: c.y + a * ct * sinP + b * st * cosP,
+    });
+  }
+  return pts;
+}
+
+/** Cox-de-Boor: Punkt auf B-Spline (Grad <= 3). */
+function bsplinePoint(degree: number, knots: number[], ctrl: Pt[], t: number): Pt {
+  const n = ctrl.length - 1;
+  let k = degree;
+  for (let i = degree; i <= n; i++) {
+    if (t >= knots[i] && t <= knots[i + 1]) { k = i; break; }
+  }
+  const d: Pt[] = [];
+  for (let j = 0; j <= degree; j++) d.push({ ...ctrl[k - degree + j] });
+  for (let r = 1; r <= degree; r++) {
+    for (let j = degree; j >= r; j--) {
+      const i = k - degree + j;
+      const denom = knots[i + degree - r + 1] - knots[i];
+      const alpha = denom === 0 ? 0 : (t - knots[i]) / denom;
+      d[j] = {
+        x: (1 - alpha) * d[j - 1].x + alpha * d[j].x,
+        y: (1 - alpha) * d[j - 1].y + alpha * d[j].y,
+      };
+    }
+  }
+  return d[degree];
+}
+
+/** SPLINE → Polyline-Approximation via de Boor (Grad <= 3). */
+function splineToPoints(entity: any): Pt[] | null {
+  const degree = entity.degreeOfSplineCurve ?? 3;
+  const ctrl = (entity.controlPoints || []) as Pt[];
+  if (!Array.isArray(ctrl) || ctrl.length < degree + 1) return null;
+  const m = ctrl.length;
+  const total = m + degree + 1;
+  const knots: number[] = entity.knotValues && entity.knotValues.length === total
+    ? entity.knotValues.slice()
+    : (() => {
+        const ks: number[] = [];
+        for (let j = 0; j < total; j++) {
+          if (j <= degree) ks.push(0);
+          else if (j >= total - 1 - degree) ks.push(1);
+          else ks.push((j - degree) / (total - 1 - 2 * degree));
+        }
+        return ks;
+      })();
+  const N = 40;
+  const t0 = knots[degree];
+  const t1 = knots[m];
+  const span = t1 - t0;
+  const pts: Pt[] = [];
+  for (let i = 0; i < N; i++) {
+    const t = t0 + (i * span) / (N - 1);
+    pts.push(bsplinePoint(degree, knots, ctrl, t));
+  }
+  return pts;
+}
+
+/** MTEXT-Formatcodes zerlegen: \P → Umbruch, Inline-Codes entfernen. */
+function cleanMText(raw: string): string {
+  return raw
+    .replace(/\\P/gi, '\n')
+    .replace(/\\~/g, ' ')
+    .replace(/\\[A-Za-z][^;{}\\]{0,12};/g, '')
+    .replace(/[{}]/g, '');
+}
+
+/**
+ * Convert a single DXF entity into a CADElement (exported for unit tests).
+ */
+export function entityToCADElement(
   entity: any,
   layerMap: Map<string, CADLayer>,
 ): CADElement | null {
@@ -84,13 +268,10 @@ function entityToCADElement(
       const s = entity.vertices?.[0];
       const e = entity.vertices?.[1];
       if (!s || !e) return null;
-      const minX = Math.min(s.x, e.x);
-      const minY = Math.min(s.y, e.y);
-      const maxX = Math.max(s.x, e.x);
-      const maxY = Math.max(s.y, e.y);
       return {
         id: nextId(), type: 'line', layerId: layer.id,
-        x: minX, y: minY, width: maxX - minX, height: maxY - minY,
+        x: Math.min(s.x, e.x), y: Math.min(s.y, e.y),
+        width: Math.abs(e.x - s.x), height: Math.abs(e.y - s.y),
         properties: { ...baseProps, x1: s.x, y1: s.y, x2: e.x, y2: e.y },
       };
     }
@@ -98,9 +279,10 @@ function entityToCADElement(
       const c = entity.center;
       const r = entity.radius;
       if (!c || r == null) return null;
+      // Center-Konvention wie beide Renderer: el.x/el.y IST das Zentrum
       return {
         id: nextId(), type: 'circle', layerId: layer.id,
-        x: c.x - r, y: c.y - r, width: r * 2, height: r * 2,
+        x: c.x, y: c.y, width: r * 2, height: r * 2,
         properties: { ...baseProps, radius: r },
       };
     }
@@ -108,25 +290,49 @@ function entityToCADElement(
       const c = entity.center;
       const r = entity.radius;
       if (!c || r == null) return null;
+      // dxf-parser konvertiert ARC-Winkel intern nach Radiant (getestet);
+      // App-Konvention ist Grad (elementDrawers, Arc-Tool, angleBetween).
+      const toDeg = (rad: number | undefined): number => ((rad ?? 0) * 180) / Math.PI;
       return {
         id: nextId(), type: 'arc', layerId: layer.id,
-        x: c.x - r, y: c.y - r, width: r * 2, height: r * 2,
-        properties: { ...baseProps, radius: r, startAngle: entity.startAngle, endAngle: entity.endAngle },
+        x: c.x, y: c.y, width: r * 2, height: r * 2,
+        properties: { ...baseProps, radius: r, startAngle: toDeg(entity.startAngle), endAngle: toDeg(entity.endAngle) },
+      };
+    }
+    case 'ELLIPSE': {
+      const pts = ellipseToPoints(entity);
+      if (!pts || pts.length < 2) return null;
+      const bbox = bboxOf(pts);
+      return {
+        id: nextId(), type: 'polyline', layerId: layer.id,
+        ...bbox,
+        properties: { ...baseProps, points: pts },
+      };
+    }
+    case 'SPLINE': {
+      const degree = entity.degreeOfSplineCurve ?? 3;
+      const ctrl = (entity.controlPoints || []) as Pt[];
+      if (degree < 1 || degree > 3) return null;
+      if (!Array.isArray(ctrl) || ctrl.length < degree + 1) return null;
+      const pts = splineToPoints(entity);
+      if (!pts || pts.length < 2) return null;
+      const bbox = bboxOf(pts);
+      return {
+        id: nextId(), type: 'polyline', layerId: layer.id,
+        ...bbox,
+        properties: { ...baseProps, points: pts },
       };
     }
     case 'LWPOLYLINE':
     case 'POLYLINE': {
       const pts = (entity.vertices || []).map((v: any) => ({ x: v.x, y: v.y }));
       if (pts.length < 2) return null;
-      const minX = Math.min(...pts.map((p: any) => p.x));
-      const minY = Math.min(...pts.map((p: any) => p.y));
-      const maxX = Math.max(...pts.map((p: any) => p.x));
-      const maxY = Math.max(...pts.map((p: any) => p.y));
+      const bbox = bboxOf(pts);
       const isClosed = entity.shape === true;
       const type: ElementType = isClosed ? 'polygon' : 'polyline';
       return {
         id: nextId(), type, layerId: layer.id,
-        x: minX, y: minY, width: maxX - minX, height: maxY - minY,
+        ...bbox,
         properties: { ...baseProps, points: pts },
       };
     }
@@ -139,16 +345,62 @@ function entityToCADElement(
         properties: { ...baseProps, text: entity.text || '', fontSize: entity.height || 12 },
       };
     }
-    case 'INSERT': {
-      // Block reference — store as block_instance
+    case 'MTEXT': {
       const pos = entity.position;
       if (!pos) return null;
+      const text = cleanMText(String(entity.text ?? ''));
+      if (!text) return null;
       return {
-        id: nextId(), type: 'block_instance', layerId: layer.id,
-        x: pos.x, y: pos.y, width: 0, height: 0,
-        properties: { ...baseProps, blockId: entity.name, scale: entity.scale || 1, rotation: entity.rotation || 0 },
+        id: nextId(), type: 'text', layerId: layer.id,
+        x: pos.x, y: pos.y, width: entity.width || 0, height: entity.height || 0,
+        properties: { ...baseProps, text, fontSize: entity.height || 12, rotation: entity.rotation || 0 },
       };
     }
+    case 'POINT': {
+      const pos = entity.position;
+      if (!pos) return null;
+      const r = 1.5;
+      return {
+        id: nextId(), type: 'circle', layerId: layer.id,
+        x: pos.x - r, y: pos.y - r, width: r * 2, height: r * 2,
+        properties: { ...baseProps, radius: r, fill: color, point: true },
+      };
+    }
+    case 'ATTDEF': {
+      const s = entity.startPoint;
+      if (!entity.tag || !s) return null;
+      return {
+        id: nextId(), type: 'text', layerId: layer.id,
+        x: s.x, y: s.y, width: 0, height: 0,
+        properties: {
+          ...baseProps,
+          text: `${entity.tag}=${entity.text ?? ''}`,
+          fontSize: entity.textHeight || 12,
+          tag: entity.tag,
+          prompt: entity.prompt ?? '',
+          attdef: true,
+        },
+      };
+    }
+    case 'HATCH': {
+      const pts = (entity.boundaryPoints || []) as Pt[];
+      if (pts.length < 3) return null;
+      const bbox = bboxOf(pts);
+      return {
+        id: nextId(), type: 'polygon', layerId: layer.id,
+        ...bbox,
+        properties: {
+          ...baseProps,
+          points: pts,
+          hatchPattern: entity.patternName || 'SOLID',
+          fill: entity.isSolid ? color : undefined,
+        },
+      };
+    }
+    case 'INSERT': {
+      const [inst] = expandInsert(entity, layerMap);
+      return inst ?? null;
+    }
     case 'DIMENSION': {
       // Basic dimension support
       const pts = entity.definitionPoint || entity.points;

frontend/src/services/dxfWriter.ts

@@ -1,23 +1,44 @@
 /**
  * DXF Writer – converts CADElement[] to DXF string
- * Minimal DXF R12 format for compatibility
+ * Zielversionen: AC1009 (R12, Default) und AC1015 (AutoCAD 2000).
+ *
+ * Task F6: BLOCKS+INSERTS mit Name-Mapping/Sanitizing, ATTDEF in
+ * Blockdefinitionen, ATTRIB/SEQEND an Instanzen mit attrValues,
+ * R12-korrektes POLYLINE+VERTEX+SEQEND statt LWPOLYLINE sowie die
+ * Center-/Winkel-Konventionen der App (el.x/el.y = Zentrum, Grad-Winkel).
  */
 import type { CADElement, CADLayer, ProjectData } from '../types/cad.types';
 
+export interface DXFWriterOptions {
+  /** Zielversion: AC1009 (R12, Default) oder AC1015. */
+  version?: 'AC1009' | 'AC1015';
+}
+
+interface Pt { x: number; y: number }
+type Write = (code: number, value: string | number) => void;
+
 /**
- * Generate a DXF R12 string from project data.
+ * Generate a DXF string from project data (R12-kompatibel).
  */
-export function writeDXF(data: ProjectData): string {
+export function writeDXF(data: ProjectData, options: DXFWriterOptions = {}): string {
+  const version = options.version ?? 'AC1009';
   const lines: string[] = [];
-  const w = (code: number, value: string | number) => {
+  const w: Write = (code, value) => {
     lines.push(String(code));
     lines.push(String(value));
   };
 
+  // ─── Name-Mapping: Block-ID → sanitierter DXF-Blockname ───
+  const usedNames = new Set<string>(['0']); // '0' ist in DXF reserviert
+  const nameMap = new Map<string, string>();
+  for (const block of data.blocks) {
+    nameMap.set(block.id, sanitizeBlockName(block.name || block.id, usedNames));
+  }
+
   // Header
   w(0, 'SECTION');
   w(2, 'HEADER');
-  w(9, '$ACADVER'); w(1, 'AC1009'); // R12
+  w(9, '$ACADVER'); w(1, version);
   w(9, '$INSBASE'); w(10, 0); w(20, 0); w(30, 0);
   w(9, '$EXTMIN'); w(10, 0); w(20, 0);
   w(9, '$EXTMAX'); w(10, 1000); w(20, 1000);
@@ -26,8 +47,6 @@ export function writeDXF(data: ProjectData): string {
   // Tables section
   w(0, 'SECTION');
   w(2, 'TABLES');
-
-  // Layer table
   w(0, 'TABLE');
   w(2, 'LAYER');
   w(70, data.layers.length);
@@ -41,15 +60,31 @@ export function writeDXF(data: ProjectData): string {
   w(0, 'ENDTAB');
   w(0, 'ENDSEC');
 
+  // ─── BLOCKS section (Task F6) ───
+  w(0, 'SECTION');
+  w(2, 'BLOCKS');
+  for (const block of data.blocks) {
+    const dxfName = nameMap.get(block.id)!;
+    w(0, 'BLOCK');
+    w(2, dxfName);
+    w(70, 0);
+    w(10, 0); w(20, 0); w(30, 0);
+    w(3, dxfName);
+    w(1, block.description || '');
+    for (const el of block.elements) {
+      writeEntity(w, el, getLayerName(data.layers, el.layerId), nameMap, true);
+    }
+    w(0, 'ENDBLK');
+  }
+  w(0, 'ENDSEC');
+
   // Entities section
   w(0, 'SECTION');
   w(2, 'ENTITIES');
-
   for (const el of data.elements) {
     const layerName = getLayerName(data.layers, el.layerId);
-    writeEntity(w, el, layerName);
+    writeEntity(w, el, layerName, nameMap, false);
   }
-
   w(0, 'ENDSEC');
 
   // EOF
@@ -58,10 +93,58 @@ export function writeDXF(data: ProjectData): string {
   return lines.join('\n');
 }
 
+/** Blocknamen für DXF sanitizen: nur [A-Za-z0-9_$-], Kollisionen deduplizieren. */
+function sanitizeBlockName(name: string, used: Set<string>): string {
+  const base = (name.replace(/[^\w$-]/g, '_') || 'BLOCK');
+  let candidate = base;
+  let i = 2;
+  while (used.has(candidate.toUpperCase())) {
+    candidate = `${base}_${i++}`;
+  }
+  used.add(candidate.toUpperCase());
+  return candidate;
+}
+
+/** R12-korrektes POLYLINE+VERTEX+SEQEND (LWPOLYLINE erst ab R13). */
+function writePolylineR12(
+  w: Write,
+  layerName: string,
+  aci: number,
+  pts: Pt[],
+  closed: boolean,
+): void {
+  w(0, 'POLYLINE');
+  w(8, layerName);
+  w(62, aci);
+  w(66, 1); // Vertices folgen
+  w(70, closed ? 1 : 0);
+  w(10, 0); w(20, 0); w(30, 0);
+  for (const pt of pts) {
+    w(0, 'VERTEX');
+    w(8, layerName);
+    w(10, pt.x); w(20, pt.y); w(30, 0);
+  }
+  w(0, 'SEQEND');
+}
+
+/** BBox-Fallback für Elemente ohne native DXF-Repräsentation. */
+function writeBBoxPolyline(w: Write, el: CADElement, layerName: string, aci: number): void {
+  const x0 = el.x;
+  const y0 = el.y;
+  writePolylineR12(w, layerName, aci, [
+    { x: x0, y: y0 },
+    { x: x0 + el.width, y: y0 },
+    { x: x0 + el.width, y: y0 + el.height },
+    { x: x0, y: y0 + el.height },
+  ], true);
+}
+
 function writeEntity(
-  w: (code: number, value: string | number) => void,
+  w: Write,
   el: CADElement,
   layerName: string,
+  nameMap: Map<string, string>,
+  inBlockDefinition: boolean,
 ): void {
   const p = el.properties;
   const stroke = (p.stroke as string) || '#ffffff';
@@ -77,68 +160,69 @@ function writeEntity(
       break;
     }
     case 'circle': {
-      const cx = el.x + el.width / 2;
-      const cy = el.y + el.height / 2;
-      const r = p.radius ?? el.width / 2;
+      // App-Konvention: el.x/el.y IST das Zentrum (beide Renderer lesen es direkt)
       w(0, 'CIRCLE');
       w(8, layerName);
       w(62, aci);
-      w(10, cx); w(20, cy); w(30, 0);
-      w(40, r);
+      w(10, el.x); w(20, el.y); w(30, 0);
+      w(40, p.radius ?? el.width / 2);
       break;
     }
     case 'arc': {
-      const cx = el.x + el.width / 2;
-      const cy = el.y + el.height / 2;
-      const r = p.radius ?? el.width / 2;
       w(0, 'ARC');
       w(8, layerName);
       w(62, aci);
-      w(10, cx); w(20, cy); w(30, 0);
-      w(40, r);
-      w(50, radToDeg(p.startAngle ?? 0));
-      w(51, radToDeg(p.endAngle ?? 360));
+      w(10, el.x); w(20, el.y); w(30, 0);
+      w(40, p.radius ?? el.width / 2);
+      // App-Konvention: Winkel in Grad (0° = 3 Uhr, CCW) — direkt schreiben
+      w(50, p.startAngle ?? 0);
+      w(51, p.endAngle ?? 360);
       break;
     }
     case 'rect': {
-      // Rectangle as LWPOLYLINE
-      w(0, 'LWPOLYLINE');
-      w(8, layerName);
-      w(62, aci);
-      w(90, 4);
-      w(70, 1); // closed
-      w(10, el.x); w(20, el.y);
-      w(10, el.x + el.width); w(20, el.y);
-      w(10, el.x + el.width); w(20, el.y + el.height);
-      w(10, el.x); w(20, el.y + el.height);
+      // App-Konvention: rect x/y = Zentrum der BBox
+      const x0 = el.x - el.width / 2;
+      const y0 = el.y - el.height / 2;
+      writePolylineR12(w, layerName, aci, [
+        { x: x0, y: y0 },
+        { x: x0 + el.width, y: y0 },
+        { x: x0 + el.width, y: y0 + el.height },
+        { x: x0, y: y0 + el.height },
+      ], true);
       break;
     }
     case 'polygon':
     case 'polyline': {
-      const pts = p.points ?? [];
-      w(0, 'LWPOLYLINE');
-      w(8, layerName);
-      w(62, aci);
-      w(90, pts.length);
-      w(70, el.type === 'polygon' ? 1 : 0);
-      for (const pt of pts) {
-        w(10, pt.x); w(20, pt.y);
+      const pts = (p.points as Pt[] | undefined) ?? [];
+      if (pts.length >= 2) {
+        writePolylineR12(w, layerName, aci, pts.map((pt) => ({ x: pt.x, y: pt.y })), el.type === 'polygon');
       }
       break;
     }
     case 'text': {
+      // ATTDEF: Text-Element als Attribut-Definition in Blockdefinitionen (Task F6)
+      if (inBlockDefinition && p.attdef === true && typeof p.tag === 'string' && p.tag) {
+        w(0, 'ATTDEF');
+        w(8, layerName);
+        w(10, el.x); w(20, el.y); w(30, 0);
+        w(40, p.fontSize ?? 12);
+        w(1, (p.text as string) ?? '');
+        w(2, p.tag);
+        w(3, (p.prompt as string) ?? '');
+        w(70, 0);
+        break;
+      }
       w(0, 'TEXT');
       w(8, layerName);
       w(62, aci);
       w(10, el.x); w(20, el.y); w(30, 0);
       w(40, p.fontSize ?? 12);
-      w(1, p.text ?? '');
+      w(1, (p.text as string) ?? '');
       break;
     }
     case 'dimension': {
-      const pts = p.points ?? [];
+      const pts = (p.points as Pt[] | undefined) ?? [];
       if (pts.length >= 2) {
-        // Draw dimension as LINE + TEXT
         w(0, 'LINE');
         w(8, layerName);
         w(62, aci);
@@ -157,27 +241,41 @@ function writeEntity(
       break;
     }
     case 'block_instance': {
+      const mapped = nameMap.get(String(p.blockId ?? ''));
+      if (!mapped) {
+        writeBBoxPolyline(w, el, layerName, aci);
+        break;
+      }
       w(0, 'INSERT');
       w(8, layerName);
       w(62, aci);
-      w(2, p.blockId ?? 'BLOCK');
+      w(2, mapped);
       w(10, el.x); w(20, el.y); w(30, 0);
-      w(41, p.scale ?? 1);
-      w(42, p.scale ?? 1);
-      w(50, radToDeg(p.rotation ?? 0));
+      const sx = typeof p.scaleX === 'number' ? p.scaleX : (typeof p.scale === 'number' ? p.scale : 1);
+      const sy = typeof p.scaleY === 'number' ? p.scaleY : (typeof p.scale === 'number' ? p.scale : 1);
+      w(41, sx);
+      w(42, sy);
+      w(50, p.rotation ?? 0); // Grad, direkt (keine radToDeg-Doppelkonvertierung)
+      // Attributwerte der Instanz → ATTRIB/SEQEND (Task F6)
+      const attrValues = p.attrValues as Record<string, string> | undefined;
+      if (attrValues && Object.keys(attrValues).length > 0) {
+        w(66, 1); // Attribute folgen
+        for (const [tag, value] of Object.entries(attrValues)) {
+          w(0, 'ATTRIB');
+          w(8, layerName);
+          w(10, el.x); w(20, el.y); w(30, 0);
+          w(40, 12);
+          w(1, value);
+          w(2, tag);
+          w(70, 0);
+        }
+        w(0, 'SEQEND');
+      }
       break;
     }
     default:
-      // For chair, seating-row, etc. — export as LWPOLYLINE bounding box
-      w(0, 'LWPOLYLINE');
-      w(8, layerName);
-      w(62, aci);
-      w(90, 4);
-      w(70, 1);
-      w(10, el.x); w(20, el.y);
-      w(10, el.x + el.width); w(20, el.y);
-      w(10, el.x + el.width); w(20, el.y + el.height);
-      w(10, el.x); w(20, el.y + el.height);
+      // chair, seating-row, table, stage, revcloud, leader, image, … → BBox
+      writeBBoxPolyline(w, el, layerName, aci);
       break;
   }
 }
@@ -191,7 +289,6 @@ function hexToACI(hex: string): number {
   const r = parseInt(h.substring(0, 2), 16);
   const g = parseInt(h.substring(2, 4), 16);
   const b = parseInt(h.substring(4, 6), 16);
-  // Map common colors to ACI
   if (r > 200 && g < 100 && b < 100) return 1; // red
   if (r > 200 && g > 200 && b < 100) return 2; // yellow
   if (r < 100 && g > 200 && b < 100) return 3; // green
@@ -200,7 +297,7 @@ function hexToACI(hex: string): number {
   if (r > 200 && g < 100 && b > 200) return 6; // magenta
   if (r > 200 && g > 200 && b > 200) return 7; // white
   if (r < 100 && g < 100 && b < 100) return 8; // gray
-  return 7; // default white
+  return 7;
 }
 
 function lineTypeToDXF(lt: string): string {
@@ -208,7 +305,3 @@ function lineTypeToDXF(lt: string): string {
   if (lt === 'dotted') return 'DOT';
   return 'CONTINUOUS';
 }
-
-function radToDeg(rad: number): number {
-  return (rad * 180) / Math.PI;
-}

frontend/src/services/importService.ts

@@ -59,8 +59,218 @@ export function importDXF(dxfString: string): ImportResult {
   }
 }
 
+/**
+ * Task F8 – SVG-Path-Parser: d-Attribut → Subpaths (Punkte + closed).
+ *
+ * Unterstützte Befehle: M/L/H/V/C/S/Q/T/A/Z — absolut und relativ (lowercase).
+ * Kubische/quadratische Bézier werden mit je 16/12 Segmenten geflattet,
+ * Arc (A) über Endpoint→Center-Parametrisierung (SVG Spec F.6.5) gesampelt.
+ * Implizite Befehlswiederholung („L 10 0 20 0") und M→L-Fortsetzung
+ * sind abgedeckt. viewBox-Offset (vbX/vbY) wird von allen Punkten abgezogen.
+ */
+interface PathPoint { x: number; y: number }
+interface PathSubpath { points: PathPoint[]; closed: boolean }
+
+function parsePathData(d: string, vbX: number, vbY: number): PathSubpath[] {
+  const tokens = d.match(/[MmLlHhVvCcSsQqTtAaZz]|-?(?:\d+\.?\d*|\.\d+)(?:[eE][-+]?\d+)?/g) ?? [];
+  const subpaths: PathSubpath[] = [];
+  let i = 0;
+  let cx = 0, cy = 0;          // aktueller Punkt
+  let sx = 0, sy = 0;          // Subpath-Start (für Z)
+  let pcx = 0, pcy = 0;       // letzter kubischer Kontrollpunkt (für S)
+  let pqx = 0, pqy = 0;       // letzter quadratischer Kontrollpunkt (für T)
+  let prevCubic = false, prevQuad = false;
+  let current: PathPoint[] | null = null;
+  let lastCmd = '';
+
+  const flush = (closed: boolean) => {
+    if (current && current.length >= 2) subpaths.push({ points: current, closed });
+    current = null;
+  };
+  const moveTo = (x: number, y: number) => {
+    flush(false);
+    current = [{ x, y }];
+    cx = x; cy = y; sx = x; sy = y;
+  };
+  const lineTo = (x: number, y: number) => {
+    if (!current) current = [{ x: cx, y: cy }];
+    current.push({ x, y });
+    cx = x; cy = y;
+  };
+  const cubicTo = (x1: number, y1: number, x2: number, y2: number, ex: number, ey: number) => {
+    const SEG = 16;
+    for (let s = 1; s <= SEG; s++) {
+      const t = s / SEG;
+      const mt = 1 - t;
+      const px = mt * mt * mt * cx + 3 * mt * mt * t * x1 + 3 * mt * t * t * x2 + t * t * t * ex;
+      const py = mt * mt * mt * cy + 3 * mt * mt * t * y1 + 3 * mt * t * t * y2 + t * t * t * ey;
+      if (!current) current = [{ x: cx, y: cy }];
+      current.push({ x: px, y: py });
+    }
+    pcx = x2; pcy = y2;
+    prevCubic = true; prevQuad = false;
+    cx = ex; cy = ey;
+  };
+  const quadTo = (x1: number, y1: number, ex: number, ey: number) => {
+    const SEG = 12;
+    for (let s = 1; s <= SEG; s++) {
+      const t = s / SEG;
+      const mt = 1 - t;
+      const px = mt * mt * cx + 2 * mt * t * x1 + t * t * ex;
+      const py = mt * mt * cy + 2 * mt * t * y1 + t * t * ey;
+      if (!current) current = [{ x: cx, y: cy }];
+      current.push({ x: px, y: py });
+    }
+    pqx = x1; pqy = y1;
+    prevQuad = true; prevCubic = false;
+    cx = ex; cy = ey;
+  };
+  const arcTo = (rx: number, ry: number, rotDeg: number, laf: number, sf: number, ex: number, ey: number) => {
+    if (rx === 0 || ry === 0 || (ex === cx && ey === cy)) { lineTo(ex, ey); return; }
+    // Endpoint → Center-Parametrisierung (SVG Spec F.6.5)
+    const rot = (rotDeg * Math.PI) / 180;
+    const cosP = Math.cos(rot), sinP = Math.sin(rot);
+    const dx = (cx - ex) / 2, dy = (cy - ey) / 2;
+    const x1p = cosP * dx + sinP * dy;
+    const y1p = -sinP * dx + cosP * dy;
+    let RX = Math.abs(rx), RY = Math.abs(ry);
+    const lambda = (x1p * x1p) / (RX * RX) + (y1p * y1p) / (RY * RY);
+    if (lambda > 1) {
+      const scale = Math.sqrt(lambda);
+      RX *= scale; RY *= scale;
+    }
+    const num = RX * RX * RY * RY - RX * RX * y1p * y1p - RY * RY * x1p * x1p;
+    const den = RX * RX * y1p * y1p + RY * RY * x1p * x1p;
+    let co = Math.sqrt(Math.max(0, den === 0 ? 0 : num / den));
+    if (laf === sf) co = -co;
+    const cxp = (co * RX * y1p) / RY;
+    const cyp = (-co * RY * x1p) / RX;
+    const ccx = cosP * cxp - sinP * cyp + (cx + ex) / 2;
+    const ccy = sinP * cxp + cosP * cyp + (cy + ey) / 2;
+    const ang = (ux: number, uy: number, vx: number, vy: number): number => {
+      const dot = ux * vx + uy * vy;
+      const len = Math.sqrt(ux * ux + uy * uy) * Math.sqrt(vx * vx + vy * vy) || 1;
+      let a = Math.acos(Math.max(-1, Math.min(1, dot / len)));
+      if (ux * vy - uy * vx < 0) a = -a;
+      return a;
+    };
+    const theta1 = ang(1, 0, (x1p - cxp) / RX, (y1p - cyp) / RY);
+    let dTheta = ang((x1p - cxp) / RX, (y1p - cyp) / RY, (-x1p - cxp) / RX, (-y1p - cyp) / RY) % (2 * Math.PI);
+    if (!sf && dTheta > 0) dTheta -= 2 * Math.PI;
+    if (sf && dTheta < 0) dTheta += 2 * Math.PI;
+    const N = 32;
+    for (let s = 1; s <= N; s++) {
+      if (!current) current = [{ x: cx, y: cy }];
+      if (s === N) {
+        // Endpunkt exakt (Float-Rundung der Trigonometrie vermeiden)
+        current.push({ x: ex, y: ey });
+        break;
+      }
+      const th = theta1 + dTheta * (s / N);
+      const px = ccx + cosP * RX * Math.cos(th) - sinP * RY * Math.sin(th);
+      const py = ccy + sinP * RX * Math.cos(th) + cosP * RY * Math.sin(th);
+      current.push({ x: px, y: py });
+    }
+    cx = ex; cy = ey;
+    prevCubic = prevQuad = false;
+  };
+
+  const readNums = (n: number): number[] => Array.from({ length: n }, () => parseFloat(tokens[i++] ?? '0'));
+  const isCmd = (t: string) => /^[MmLlHhVvCcSsQqTtAaZz]$/.test(t);
+
+  while (i < tokens.length) {
+    let cmd = tokens[i++];
+    if (!isCmd(cmd)) {
+      // implizite Wiederholung des letzten Befehls; nach M gilt L
+      i--;
+      if (!lastCmd) break;
+      cmd = lastCmd === 'M' ? 'L' : lastCmd === 'm' ? 'l' : lastCmd;
+    } else {
+      lastCmd = cmd;
+    }
+    const up = cmd.toUpperCase();
+    const abs = cmd === up;
+    switch (up) {
+      case 'M': {
+        const [x, y] = readNums(2);
+        moveTo(abs ? x - vbX : cx + x, abs ? y - vbY : cy + y);
+        break;
+      }
+      case 'L': {
+        const [x, y] = readNums(2);
+        lineTo(abs ? x - vbX : cx + x, abs ? y - vbY : cy + y);
+        break;
+      }
+      case 'H': {
+        const [x] = readNums(1);
+        lineTo(abs ? x - vbX : cx + x, cy);
+        break;
+      }
+      case 'V': {
+        const [y] = readNums(1);
+        lineTo(cx, abs ? y - vbY : cy + y);
+        break;
+      }
+      case 'C': {
+        const n = readNums(6);
+        cubicTo(
+          abs ? n[0] - vbX : cx + n[0], abs ? n[1] - vbY : cy + n[1],
+          abs ? n[2] - vbX : cx + n[2], abs ? n[3] - vbY : cy + n[3],
+          abs ? n[4] - vbX : cx + n[4], abs ? n[5] - vbY : cy + n[5],
+        );
+        break;
+      }
+      case 'S': {
+        const n = readNums(4);
+        const x1 = prevCubic ? 2 * cx - pcx : cx;
+        const y1 = prevCubic ? 2 * cy - pcy : cy;
+        cubicTo(
+          x1, y1,
+          abs ? n[0] - vbX : cx + n[0], abs ? n[1] - vbY : cy + n[1],
+          abs ? n[2] - vbX : cx + n[2], abs ? n[3] - vbY : cy + n[3],
+        );
+        break;
+      }
+      case 'Q': {
+        const n = readNums(4);
+        quadTo(
+          abs ? n[0] - vbX : cx + n[0], abs ? n[1] - vbY : cy + n[1],
+          abs ? n[2] - vbX : cx + n[2], abs ? n[3] - vbY : cy + n[3],
+        );
+        break;
+      }
+      case 'T': {
+        const n = readNums(2);
+        const x1 = prevQuad ? 2 * cx - pqx : cx;
+        const y1 = prevQuad ? 2 * cy - pqy : cy;
+        quadTo(x1, y1, abs ? n[0] - vbX : cx + n[0], abs ? n[1] - vbY : cy + n[1]);
+        break;
+      }
+      case 'A': {
+        const n = readNums(7);
+        arcTo(
+          n[0], n[1], n[2], n[3], n[4],
+          abs ? n[5] - vbX : cx + n[5], abs ? n[6] - vbY : cy + n[6],
+        );
+        break;
+      }
+      case 'Z': {
+        // Polygon schließt automatisch — keinen duplizierten Endpunkt anhängen
+        flush(true);
+        cx = sx; cy = sy;
+        prevCubic = prevQuad = false;
+        break;
+      }
+    }
+  }
+  flush(false);
+  return subpaths;
+}
+
 /**
  * Import SVG string — converts SVG elements to CAD elements.
+ * Task F8: path-Support (M/L/H/V/C/S/Q/T/A/Z), rect/circle in App-Konvention
+ * (x/y = Zentrum), ellipse als geschlossenes Polygon.
  */
 export function importSVG(svgString: string): ImportResult {
   try {
@@ -79,6 +289,12 @@ export function importSVG(svgString: string): ImportResult {
       vbY = parts[1] || 0;
     }
 
+    const bboxOf = (pts: PathPoint[]) => {
+      const xs = pts.map((p) => p.x), ys = pts.map((p) => p.y);
+      const minX = Math.min(...xs), minY = Math.min(...ys);
+      return { x: minX, y: minY, width: Math.max(...xs) - minX, height: Math.max(...ys) - minY };
+    };
+
     // Process SVG elements
     const processElement = (node: Element) => {
       const tag = node.tagName.toLowerCase();
@@ -101,38 +317,50 @@ export function importSVG(svgString: string): ImportResult {
           break;
         }
         case 'rect': {
+          // App-Konvention (Task F8): rect x/y = Zentrum der BBox
           const x = parseFloat(node.getAttribute('x') || '0') - vbX;
           const y = parseFloat(node.getAttribute('y') || '0') - vbY;
           const w = parseFloat(node.getAttribute('width') || '0');
           const h = parseFloat(node.getAttribute('height') || '0');
           elements.push({
             id: nextId(), type: 'rect', layerId: 'layer-0',
-            x, y, width: w, height: h,
+            x: x + w / 2, y: y + h / 2, width: w, height: h,
             properties: { stroke, strokeWidth, fill: fill !== 'none' ? fill : undefined },
           });
           break;
         }
         case 'circle': {
+          // App-Konvention (Task F8): el.x/el.y = Zentrum direkt (Renderer liest es so)
           const cx = parseFloat(node.getAttribute('cx') || '0') - vbX;
           const cy = parseFloat(node.getAttribute('cy') || '0') - vbY;
           const r = parseFloat(node.getAttribute('r') || '0');
           elements.push({
             id: nextId(), type: 'circle', layerId: 'layer-0',
-            x: cx - r, y: cy - r, width: r * 2, height: r * 2,
-            properties: { stroke, strokeWidth, radius: r },
+            x: cx, y: cy, width: r * 2, height: r * 2,
+            properties: { stroke, strokeWidth, radius: r, fill: fill !== 'none' ? fill : undefined },
           });
           break;
         }
         case 'ellipse': {
+          // Task F8: echte Ellipse als geschlossenes Polygon (64 Punkte),
+          // statt Kreis mit max(rx, ry)
           const cx = parseFloat(node.getAttribute('cx') || '0') - vbX;
           const cy = parseFloat(node.getAttribute('cy') || '0') - vbY;
           const rx = parseFloat(node.getAttribute('rx') || '0');
           const ry = parseFloat(node.getAttribute('ry') || '0');
-          elements.push({
-            id: nextId(), type: 'circle', layerId: 'layer-0',
-            x: cx - rx, y: cy - ry, width: rx * 2, height: ry * 2,
-            properties: { stroke, strokeWidth, radius: Math.max(rx, ry) },
-          });
+          const pts: PathPoint[] = [];
+          const N = 64;
+          for (let s = 0; s < N; s++) {
+            const t = (s / N) * Math.PI * 2;
+            pts.push({ x: cx + rx * Math.cos(t), y: cy + ry * Math.sin(t) });
+          }
+          if (pts.length >= 3) {
+            elements.push({
+              id: nextId(), type: 'polygon', layerId: 'layer-0',
+              ...bboxOf(pts),
+              properties: { stroke, strokeWidth, points: pts, fill: fill !== 'none' ? fill : undefined },
+            });
+          }
           break;
         }
         case 'polyline':
@@ -144,14 +372,26 @@ export function importSVG(svgString: string): ImportResult {
             return acc;
           }, []);
           if (pts.length >= 2) {
-            const minX = Math.min(...pts.map(p => p.x));
-            const minY = Math.min(...pts.map(p => p.y));
-            const maxX = Math.max(...pts.map(p => p.x));
-            const maxY = Math.max(...pts.map(p => p.y));
             elements.push({
               id: nextId(), type: tag === 'polygon' ? 'polygon' : 'polyline', layerId: 'layer-0',
-              x: minX, y: minY, width: maxX - minX, height: maxY - minY,
-              properties: { stroke, strokeWidth, points: pts },
+              ...bboxOf(pts),
+              properties: { stroke, strokeWidth, points: pts, fill: fill !== 'none' ? fill : undefined },
+            });
+          }
+          break;
+        }
+        case 'path': {
+          // Task F8: d-Attribut → Subpaths (polyline/polygon je Z-Flag)
+          const d = node.getAttribute('d') || '';
+          for (const sub of parsePathData(d, vbX, vbY)) {
+            elements.push({
+              id: nextId(), type: sub.closed ? 'polygon' : 'polyline', layerId: 'layer-0',
+              ...bboxOf(sub.points),
+              properties: {
+                stroke, strokeWidth,
+                points: sub.points,
+                fill: sub.closed && fill !== 'none' ? fill : undefined,
+              },
             });
           }
           break;
@@ -189,6 +429,22 @@ export function importSVG(svgString: string): ImportResult {
   }
 }
 
+/**
+ * Task F8 – SVG als Block-Payload für die globale Bibliothek.
+ *
+ * Liefert die echte Geometrie (CADElement-Array als JSON-String) plus das
+ * Original-SVG als Thumbnail. Ohne Geometrie (z.B. nur <defs>) ist
+ * blockData null — der Caller fällt dann auf den {type:'svg'}-Raw-Fallback
+ * zurück.
+ */
+export function importSVGAsBlockPayload(svgString: string): { blockData: string | null; svg: string } {
+  const res = importSVG(svgString);
+  return {
+    blockData: res.success && res.elements.length > 0 ? JSON.stringify(res.elements) : null,
+    svg: svgString,
+  };
+}
+
 /**
  * Import JSON project file.
  */

frontend/src/services/pdfExport.ts

@@ -3,6 +3,15 @@
  */
 import { PDFDocument, rgb, StandardFonts } from 'pdf-lib';
 import type { CADElement, CADLayer, ProjectData } from '../types/cad.types';
+import { elementToPrimitives, type ShapePrimitive } from '../render/pixi/elementDrawers';
+import type { CADDocument } from '../kernel/document/CADDocument';
+
+export interface LayoutPDFOptions {
+  /** Alles in Schwarz drucken (Task G4). */
+  monochrome?: boolean;
+  /** Seitenränder in pt (Default 20). */
+  margin?: number;
+}
 
 /**
  * Export project data to a PDF byte array.
@@ -172,3 +181,196 @@ function hexToRgb(hex: string | undefined): ReturnType<typeof rgb> | null {
   const b = parseInt(h.substring(4, 6), 16) / 255;
   return rgb(r, g, b);
 }
+
+
+// ═══════════════════════════════════════════════════════════
+// Task G4 — PDF-Export je Layout im Ausgabemaßstab
+// ═══════════════════════════════════════════════════════════
+
+/** A4 landscape in Punkten. */
+const A4_LANDSCAPE_W = 842;
+const A4_LANDSCAPE_H = 595;
+
+/**
+ * Exportiert EIN Layout als PDF (A4 landscape).
+ *
+ * Der gespeicherte Viewport (center/scale) definiert den sichtbaren
+ * Welt-Ausschnitt; die Zeichnung wird in den Ausgabemaßstab skaliert
+ * (Welt-pt × viewport.scale). Geometrie läuft über elementToPrimitives
+ * (C2) — identische Konventionen wie Pixi-Renderer (circle el.x/el.y =
+ * Zentrum). Linienbreiten: properties.strokeWidth, andernfalls Linientyp
+ * aus dem Layer (solid 0.7pt, dashed 0.9pt, dotted 0.5pt) mit passenden
+ * Dash-Patterns. `monochrome` erzwingt Schwarz. Der Titelblock aus
+ * layout.frameBlockRef wird mitgezeichnet (unskaliert als Rahmen unten
+ * rechts, Elemente relativ zur Ecke).
+ */
+export async function exportLayoutPDF(
+  doc: CADDocument,
+  layoutId: string,
+  options: LayoutPDFOptions = {},
+): Promise<Uint8Array> {
+  const layout = doc.getLayout(layoutId);
+  if (!layout) throw new Error(`exportLayoutPDF: Layout '${layoutId}' nicht gefunden`);
+
+  const margin = options.margin ?? 20;
+  const pdfDoc = await PDFDocument.create();
+  const font = await pdfDoc.embedFont(StandardFonts.Helvetica);
+  const page = pdfDoc.addPage([A4_LANDSCAPE_W, A4_LANDSCAPE_H]);
+  const mono = options.monochrome === true;
+
+  const layers = doc.getAllLayers();
+  const visibleLayerIds = new Set(layers.filter((l) => l.visible).map((l) => l.id));
+  const layerById = new Map(layers.map((l) => [l.id, l]));
+
+  // ── Ausgabemaßstab: Welt → pt ──
+  const scale = layout.viewport.scale;
+  const viewW = (A4_LANDSCAPE_W - 2 * margin) / scale;
+  const viewH = (A4_LANDSCAPE_H - 2 * margin) / scale;
+  const worldMinX = layout.viewport.center.x - viewW / 2;
+  const worldMinY = layout.viewport.center.y - viewH / 2;
+
+  // PDF-Y-Achse zeigt nach OBEN (bottom-left origin) — CAD nach unten:
+  const toPage = (wx: number, wy: number): { x: number; y: number } => ({
+    x: margin + (wx - worldMinX) * scale,
+    y: A4_LANDSCAPE_H - margin - (wy - worldMinY) * scale,
+  });
+
+  const colorFor = (el: CADElement): ReturnType<typeof rgb> => {
+    if (mono) return rgb(0, 0, 0);
+    const layer = layerById.get(el.layerId);
+    const hex = (el.properties.stroke as string | undefined) ?? layer?.color;
+    return hexToRgb(hex) ?? rgb(0, 0, 0);
+  };
+
+  const lineWidthFor = (el: CADElement): number => {
+    const explicit = el.properties.strokeWidth as number | undefined;
+    if (typeof explicit === 'number' && explicit > 0) return explicit;
+    const layer = layerById.get(el.layerId);
+    switch (layer?.lineType) {
+      case 'dashed': return 0.9;
+      case 'dotted': return 0.5;
+      default: return 0.7;
+    }
+  };
+
+  const dashFor = (el: CADElement): number[] | undefined => {
+    if (mono) return undefined;
+    const layer = layerById.get(el.layerId);
+    if (layer?.lineType === 'dashed') return [4, 3];
+    if (layer?.lineType === 'dotted') return [0.5, 2];
+    return undefined;
+  };
+
+  const drawPrimitives = (els: CADElement[], transform: (wx: number, wy: number) => { x: number; y: number }, scaleOverride?: number): void => {
+    for (const el of els) {
+      if (!visibleLayerIds.has(el.layerId)) continue;
+      const prims = elementToPrimitives(el);
+      const lw = lineWidthFor(el) * (scaleOverride ?? scale);
+      const dash = dashFor(el);
+      const color = colorFor(el);
+      for (const prim of prims) {
+        drawPrimitive(page, prim, transform, lw, color, dash, font, mono);
+      }
+    }
+  };
+
+  // ── Modellinhalt ──
+  drawPrimitives(doc.getAllElements(), toPage);
+
+  // ── Titelblock (frameBlockRef) unten rechts, unskaliert ──
+  if (layout.frameBlockRef) {
+    const block = doc.getBlock(layout.frameBlockRef);
+    if (block) {
+      const FRAME_MARGIN = 12;
+      // Block-Elemente liegen um (0,0) herum — an Ecke unten rechts verschieben
+      const frameOriginX = A4_LANDSCAPE_W - margin - 190 - FRAME_MARGIN;
+      const frameOriginY = margin + FRAME_MARGIN;
+      const frameTransform = (wx: number, wy: number) => ({
+        x: frameOriginX + wx,
+        y: frameOriginY + wy,
+      });
+      drawPrimitives(block.elements, frameTransform, 1);
+    }
+  }
+
+  return pdfDoc.save();
+}
+
+/** Zeichnet ein einzelnes ShapePrimitive auf die PDF-Seite. */
+function drawPrimitive(
+  page: any,
+  prim: ShapePrimitive,
+  transform: (wx: number, wy: number) => { x: number; y: number },
+  lineWidth: number,
+  color: ReturnType<typeof rgb>,
+  dash: number[] | undefined,
+  font: any,
+  mono: boolean,
+): void {
+  switch (prim.kind) {
+    case 'line': {
+      const s = transform(prim.from.x, prim.from.y);
+      const e = transform(prim.to.x, prim.to.y);
+      page.drawLine({ start: s, end: e, thickness: lineWidth, color, dashArray: dash });
+      break;
+    }
+    case 'rect': {
+      const tl = transform(prim.x, prim.y + prim.h);
+      page.drawRectangle({
+        x: tl.x, y: tl.y, width: prim.w, height: prim.h,
+        borderColor: color, borderWidth: lineWidth,
+        ...(prim.fill ? { color: hexToRgb(prim.fill) ?? color } : {}),
+      });
+      break;
+    }
+    case 'circle': {
+      const c = transform(prim.center.x, prim.center.y);
+      page.drawCircle({
+        x: c.x, y: c.y, radius: prim.radius,
+        borderColor: color, borderWidth: lineWidth,
+        ...(prim.fill ? { color: hexToRgb(prim.fill) ?? color } : {}),
+      });
+      break;
+    }
+    case 'arc': {
+      // Arc → 32 Liniensegmente (Grad, 0° = 3 Uhr, CCW — CAD-Konvention)
+      const c = transform(prim.center.x, prim.center.y);
+      const SEG = 32;
+      const a0 = (prim.startDeg * Math.PI) / 180;
+      const a1 = (prim.endDeg * Math.PI) / 180;
+      let span = a1 - a0;
+      if (span <= 0) span += 2 * Math.PI;
+      let prev = { x: c.x + Math.cos(a0) * prim.radius, y: c.y + Math.sin(a0) * prim.radius };
+      for (let i = 1; i <= SEG; i++) {
+        const a = a0 + (span * i) / SEG;
+        const pt = { x: c.x + Math.cos(a) * prim.radius, y: c.y + Math.sin(a) * prim.radius };
+        page.drawLine({ start: prev, end: pt, thickness: lineWidth, color, dashArray: dash });
+        prev = pt;
+      }
+      break;
+    }
+    case 'polyline': {
+      for (let i = 0; i < prim.points.length - 1; i++) {
+        const s = transform(prim.points[i].x, prim.points[i].y);
+        const e = transform(prim.points[i + 1].x, prim.points[i + 1].y);
+        page.drawLine({ start: s, end: e, thickness: lineWidth, color, dashArray: dash });
+      }
+      if (prim.close && prim.points.length > 2) {
+        const s = transform(prim.points[prim.points.length - 1].x, prim.points[prim.points.length - 1].y);
+        const e = transform(prim.points[0].x, prim.points[0].y);
+        page.drawLine({ start: s, end: e, thickness: lineWidth, color, dashArray: dash });
+      }
+      break;
+    }
+    case 'text': {
+      const at = transform(prim.at.x, prim.at.y);
+      page.drawText(prim.text, {
+        x: at.x, y: at.y - prim.fontSize,
+        size: prim.fontSize,
+        font,
+        color: mono ? rgb(0, 0, 0) : (hexToRgb(prim.color) ?? color),
+      });
+      break;
+    }
+  }
+}

frontend/src/services/printService.ts

@@ -0,0 +1,37 @@
+/**
+ * Task G5 – Browser-Print-Service.
+ *
+ * Bereitet die App für window.print() vor: Der Body erhält die Klasse
+ * `print-layout`, das @media print Stylesheet blendet das UI-Chrome aus
+ * und zeigt nur den Druckbereich (Canvas/Layout). Nach dem Druck wird
+ * die Klasse wieder entfernt (kein DOM-Mutation-Restzustand).
+ */
+
+const PRINT_CLASS = 'print-layout';
+
+/** Setzt den Print-Modus (Body-Klasse; @media print regelt das Rendering). */
+export function preparePrintLayout(): void {
+  document.body.classList.add(PRINT_CLASS);
+}
+
+/** Entfernt den Print-Modus (nach Druck oder bei Abbruch). */
+export function cleanupPrintLayout(): void {
+  document.body.classList.remove(PRINT_CLASS);
+}
+
+/**
+ * Druck-Flow: Vorbereitung → Rendern der nächsten Frames (Styles müssen
+ * greifen, bevor der Browser den Print-Dialog aufbaut) → window.print
+ * → Aufräumen. await-fähig für Tests (window.print wird gemockt).
+ */
+export async function printLayout(): Promise<void> {
+  preparePrintLayout();
+  // Zwei Frames warten: Style-Anwendung + Layout der Print-Ansicht
+  await new Promise<void>((resolve) => requestAnimationFrame(() => resolve()));
+  await new Promise<void>((resolve) => requestAnimationFrame(() => resolve()));
+  try {
+    window.print();
+  } finally {
+    cleanupPrintLayout();
+  }
+}

frontend/src/services/projectTemplates.ts

@@ -0,0 +1,136 @@
+/**
+ * Task H2 – Projekt-Templates: Branchen-Presets als Startzustand.
+ *
+ * Jedes Preset definiert: gridSize + unit (Raster), Layer-Set,
+ * enabledPlugins (welche V2-Plugins aktiviert werden) und einen
+ * libraryFolderSeed (Startordner der Block-Bibliothek).
+ */
+import type { CADLayer } from '../types/cad.types';
+import type { CADDocument } from '../kernel/document/CADDocument';
+
+export type ProjectTemplateId = 'halle' | 'openair' | 'saal' | 'messe' | 'buero' | 'garten';
+
+export interface ProjectTemplate {
+  id: ProjectTemplateId;
+  name: string;
+  description: string;
+  gridSize: number;
+  unit: 'mm' | 'cm' | 'm';
+  layers: CADLayer[];
+  enabledPlugins: string[];
+  libraryFolderSeed: string;
+}
+
+function layer(id: string, name: string, color: string, sortOrder: number): CADLayer {
+  return {
+    id, name, visible: true, locked: false,
+    color, lineType: 'solid', transparency: 0, sortOrder, parentId: null,
+  };
+}
+
+export const PROJECT_TEMPLATES: ProjectTemplate[] = [
+  {
+    id: 'halle',
+    name: 'Halle',
+    description: 'Veranstaltungshalle: Bestuhlung, Bühne, Technik, Wege',
+    gridSize: 100,
+    unit: 'cm',
+    layers: [
+      layer('tpl-h-wand', 'Wände', '#8a8f98', 0),
+      layer('tpl-h-bestuhlung', 'Bestuhlung', '#4a90d9', 1),
+      layer('tpl-h-buehne', 'Bühne', '#c0392b', 2),
+      layer('tpl-h-technik', 'Technik', '#f39c12', 3),
+    ],
+    enabledPlugins: ['event-tools', 'core-drawing', 'core-modify', 'core-annotate', 'builtin-library'],
+    libraryFolderSeed: 'Veranstaltungstechnik',
+  },
+  {
+    id: 'openair',
+    name: 'OpenAir',
+    description: 'Open-Air-Gelände: Zonen, Bestuhlung, Absperrungen, Wege',
+    gridSize: 100,
+    unit: 'cm',
+    layers: [
+      layer('tpl-o-zonen', 'Zonen', '#27ae60', 0),
+      layer('tpl-o-bestuhlung', 'Bestuhlung', '#4a90d9', 1),
+      layer('tpl-o-absperrung', 'Absperrung', '#c0392b', 2),
+      layer('tpl-o-wege', 'Wege', '#b8a888', 3),
+    ],
+    enabledPlugins: ['event-tools', 'core-drawing', 'core-modify', 'core-annotate', 'builtin-library'],
+    libraryFolderSeed: 'OpenAir',
+  },
+  {
+    id: 'saal',
+    name: 'Saal',
+    description: 'Festsaal: Bestuhlung, Bühne, Catering, Deko',
+    gridSize: 50,
+    unit: 'cm',
+    layers: [
+      layer('tpl-s-bestuhlung', 'Bestuhlung', '#4a90d9', 0),
+      layer('tpl-s-buehne', 'Bühne', '#c0392b', 1),
+      layer('tpl-s-catering', 'Catering', '#f39c12', 2),
+      layer('tpl-s-deko', 'Deko', '#9b59b6', 3),
+    ],
+    enabledPlugins: ['event-tools', 'core-drawing', 'core-modify', 'core-annotate', 'builtin-library'],
+    libraryFolderSeed: 'Eventservice',
+  },
+  {
+    id: 'messe',
+    name: 'Messe',
+    description: 'Messestand: Standlayout, Theken, Medien, Strom',
+    gridSize: 10,
+    unit: 'mm',
+    layers: [
+      layer('tpl-m-stand', 'Standlayout', '#e74c3c', 0),
+      layer('tpl-m-theken', 'Theken', '#f39c12', 1),
+      layer('tpl-m-medien', 'Medien', '#3498db', 2),
+      layer('tpl-m-strom', 'Strom', '#f1c40f', 3),
+    ],
+    enabledPlugins: ['core-drawing', 'core-modify', 'core-annotate', 'builtin-library'],
+    libraryFolderSeed: 'Messebau',
+  },
+  {
+    id: 'buero',
+    name: 'Büro',
+    description: 'Büroplanung: Möbel, Wände, Netzwerk, Beschriftung',
+    gridSize: 10,
+    unit: 'mm',
+    layers: [
+      layer('tpl-b-waende', 'Wände', '#8a8f98', 0),
+      layer('tpl-b-moebel', 'Möbel', '#4a90d9', 1),
+      layer('tpl-b-netzwerk', 'Netzwerk', '#27ae60', 2),
+      layer('tpl-b-text', 'Beschriftung', '#9aa0a6', 3),
+    ],
+    enabledPlugins: ['core-drawing', 'core-modify', 'core-annotate', 'builtin-library'],
+    libraryFolderSeed: 'Büroeinrichtung',
+  },
+  {
+    id: 'garten',
+    name: 'Garten',
+    description: 'Gartenplanung: Bepflanzung, Wege, Wasser, Beleuchtung',
+    gridSize: 100,
+    unit: 'cm',
+    layers: [
+      layer('tpl-g-bepflanzung', 'Bepflanzung', '#27ae60', 0),
+      layer('tpl-g-wege', 'Wege', '#b8a888', 1),
+      layer('tpl-g-wasser', 'Wasser', '#3498db', 2),
+      layer('tpl-g-licht', 'Beleuchtung', '#f1c40f', 3),
+    ],
+    enabledPlugins: ['core-drawing', 'core-modify', 'core-annotate', 'builtin-library'],
+    libraryFolderSeed: 'Gartenlandschaft',
+  },
+];
+
+/** Template per ID (oder undefined). */
+export function getProjectTemplate(id: string): ProjectTemplate | undefined {
+  return PROJECT_TEMPLATES.find((t) => t.id === id);
+}
+
+/**
+ * Überträgt ein Template auf ein Dokument: Layer-Set wird ERSETZT
+ * (Template = Startzustand). Grid/unit/pluginSeed sind UI-Einstellungen,
+ * die der Aufrufer aus dem Template liest.
+ */
+export function applyProjectTemplate(doc: CADDocument, tpl: ProjectTemplate): void {
+  doc.replaceLayers(tpl.layers);
+}

frontend/src/services/seatingService.ts

@@ -159,6 +159,13 @@ export const SEATING_TEMPLATES: SeatingTemplate[] = [
   },
 ];
 
+let seqCounter = 0;
+/** Eindeutige, kollisionsfreie ID mit Präfix (Zeit + Sequenz + Zufall). */
+function nextUid(prefix: string): string {
+  seqCounter += 1;
+  return `${prefix}_${Date.now().toString(36)}_${seqCounter.toString(36)}_${Math.random().toString(36).slice(2, 8)}`;
+}
+
 export class SeatingService {
   private generateId(): string {
     return `el_${Date.now()}_${Math.random().toString(36).slice(2, 9)}`;
@@ -189,6 +196,7 @@ export class SeatingService {
   createSeatingRow(x: number, y: number, layerId: string, config: Partial<SeatingRowConfig> = {}): CADElement[] {
     const cfg = { ...DEFAULT_ROW, ...config };
     const elements: CADElement[] = [];
+    const rowId = nextUid('row');
     const totalWidth = (cfg.count - 1) * cfg.spacing + cfg.chairWidth;
     const startX = x - totalWidth / 2 + cfg.chairWidth / 2;
 
@@ -217,7 +225,7 @@ export class SeatingService {
           outlineColor: '#2a5a99',
           seatType: 'standard',
           rowIndex: i,
-          rowId: `row_${Date.now()}`,
+          rowId,
         },
       });
     }
@@ -233,9 +241,10 @@ export class SeatingService {
     const startX = x - totalW / 2 + cfg.chairWidth / 2;
     const startY = y - totalH / 2 + cfg.chairHeight / 2;
     const rot = cfg.rotation * Math.PI / 180;
-    const blockId = `block_${Date.now()}`;
+    const blockId = nextUid('block');
 
     for (let row = 0; row < cfg.rows; row++) {
+      const rowId = nextUid('row');
       const offset = cfg.rowOffset * (row % 2);
       for (let col = 0; col < cfg.cols; col++) {
         const lx = startX + col * cfg.colSpacing + offset;
@@ -263,6 +272,7 @@ export class SeatingService {
             rowIndex: row,
             colIndex: col,
             blockId,
+            rowId,
           },
         });
       }
@@ -270,6 +280,47 @@ export class SeatingService {
     return elements;
   }
 
+  /** Create an arc row (curved seating around a center point) — Task E2 */
+  createArcRow(
+    centerX: number,
+    centerY: number,
+    radius: number,
+    startAngleDeg: number,
+    endAngleDeg: number,
+    layerId: string,
+    spacing = 50,
+  ): CADElement[] {
+    const arcLen = Math.abs(endAngleDeg - startAngleDeg) * Math.PI / 180 * radius;
+    const count = Math.max(2, Math.floor(arcLen / spacing));
+    const rowId = `arcrow_${Date.now().toString(36)}_${Math.random().toString(36).slice(2, 8)}`;
+    const elements: CADElement[] = [];
+    for (let i = 0; i <= count; i++) {
+      const angle = startAngleDeg + (endAngleDeg - startAngleDeg) * (i / count);
+      const rad = angle * Math.PI / 180;
+      const px = centerX + radius * Math.cos(rad);
+      const py = centerY + radius * Math.sin(rad);
+      elements.push({
+        id: this.generateId(),
+        type: 'chair',
+        layerId,
+        x: px,
+        y: py,
+        width: 45,
+        height: 45,
+        properties: {
+          rotation: angle + 90,
+          fill: '#4a90d9',
+          backrestColor: '#3a7ac9',
+          outlineColor: '#2a5a99',
+          seatType: 'standard',
+          rowIndex: i,
+          rowId,
+        },
+      });
+    }
+    return elements;
+  }
+
   /** Create a table element */
   createTable(x: number, y: number, layerId: string, config: Partial<TableConfig> = {}): CADElement {
     const cfg = { ...DEFAULT_TABLE, ...config };
@@ -308,6 +359,7 @@ export class SeatingService {
         stroke: '#1a2e3f',
         strokeWidth: 2,
         label: cfg.label,
+        height: cfg.height, // Bühnenhöhe in cm (Task E7: stage height attr)
       },
     };
   }
@@ -342,8 +394,18 @@ export class SeatingService {
     return [];
   }
 
-  /** Count seats in a list of elements */
-  countSeats(elements: CADElement[]): { total: number; byRow: Record<string, number>; byBlock: Record<string, number> } {
+/**
+ * Zählt Sitzplätze gruppiert nach Reihe und Block.
+ * byRow enthält Reihen aus freien Reihen UND Block-Reihen (seit BUG-1-Fix
+ * tragen Block-Stühle pro Reihe eine eigene rowId).
+ */
+  countSeats(elements: CADElement[]): {
+    total: number;
+    byRow: Record<string, number>;
+    byBlock: Record<string, number>;
+    /** Platzhalter für künftige Zonen-Gruppierung (aktuell immer leer). */
+    byZone?: Record<string, number>;
+  } {
     let total = 0;
     const byRow: Record<string, number> = {};
     const byBlock: Record<string, number> = {};
@@ -364,6 +426,23 @@ export class SeatingService {
     return { total, byRow, byBlock };
   }
 
+  /**
+   * Task E5: Exportiert eine Sitzplatzliste als CSV-String.
+   * Spalten: Typ, rowId, blockId, X, Y
+   * Zeilentrenner: \n (kompatibel mit Excel via „Daten importieren“).
+   */
+  exportSeatListCSV(elements: CADElement[]): string {
+    const header = 'type,row_id,block_id,x,y';
+    const rows: string[] = [header];
+    for (const el of elements) {
+      if (el.type !== 'chair') continue;
+      const rowId = (el.properties.rowId as string | undefined) ?? '';
+      const blockId = (el.properties.blockId as string | undefined) ?? '';
+      rows.push(`chair,${rowId},${blockId},${el.x.toFixed(1)},${el.y.toFixed(1)}`);
+    }
+    return rows.join('\n');
+  }
+
   /** Get all chairs belonging to a specific row */
   getRowElements(elements: CADElement[], rowId: string): CADElement[] {
     return elements.filter(el => el.type === 'chair' && el.properties.rowId === rowId);

frontend/src/services/titleBlockService.ts

@@ -0,0 +1,146 @@
+/**
+ * Task G3 – Titelblock-Service.
+ *
+ * Erzeugt eine Titelblock-Blockdefinition mit attributierten Texten
+ * (Projekt/Datum/Maßstab/Autor) nach der ATTDEF-Konvention aus F5/F6
+ * (properties.tag + attdef:true + text 'TAG=Wert'), sodass:
+ * - der DXF-Writer (F6) sie als ATTDEF in Blockdefinitionen exportiert
+ * - das spätere PropertiesPanel (D12) daraus ein Formular bauen kann
+ * - Layouts über frameBlockRef referenzieren (G1)
+ */
+import type { CADElement, BlockDefinition } from '../types/cad.types';
+import type { CADDocument } from '../kernel/document/CADDocument';
+
+export const TITLE_BLOCK_NAME = 'Titelblock A4';
+
+export interface TitleBlockMeta {
+  project?: string;
+  date?: string;
+  scale?: string;
+  author?: string;
+}
+
+interface AttrSlot {
+  tag: string;
+  prompt: string;
+  /** Position der Textzeile relativ zum Block-Ursprung (unten-links im Rahmen). */
+  dx: number;
+  dy: number;
+}
+
+const SLOTS: AttrSlot[] = [
+  { tag: 'PROJEKT', prompt: 'Projektname', dx: 10, dy: 18 },
+  { tag: 'DATUM', prompt: 'Datum der Zeichnung', dx: 10, dy: 36 },
+  { tag: 'MASSSTAB', prompt: 'Zeichnungsmaßstab', dx: 10, dy: 54 },
+  { tag: 'AUTOR', prompt: 'Bearbeiter/Autor', dx: 10, dy: 72 },
+];
+
+const FRAME_W = 180;
+const FRAME_H = 100;
+const FALLBACK = '\u2014'; // —
+
+let idSeq = 0;
+function nid(prefix: string): string {
+  return `titleblk-${prefix}-${Date.now()}-${idSeq++}`;
+}
+
+/**
+ * Titelblock-Elemente: Rahmen (Zentrum 0,0) + Titel + 4 attributierte Texte.
+ * Rein — keine Doc-Interaktion (unit-testbar).
+ */
+export function createTitleBlockElements(meta: TitleBlockMeta): CADElement[] {
+  const els: CADElement[] = [];
+
+  // Rahmen: rect in App-Konvention (x/y = Zentrum), Umriss unten-links
+  els.push({
+    id: nid('frame'),
+    type: 'rect',
+    layerId: 'layer-0',
+    x: 0,
+    y: 0,
+    width: FRAME_W,
+    height: FRAME_H,
+    properties: {
+      stroke: '#e0e0e0',
+      strokeWidth: 1.5,
+      fill: 'none',
+    },
+  });
+
+  // Titel (kein Attribut — fester Blockname als Beschriftung)
+  els.push({
+    id: nid('title'),
+    type: 'text',
+    layerId: 'layer-0',
+    x: FRAME_W / 2 - 10,
+    y: FRAME_H / 2 - 6,
+    width: 0,
+    height: 0,
+    properties: {
+      text: TITLE_BLOCK_NAME,
+      fontSize: 10,
+      stroke: '#9aa0a6',
+    },
+  });
+
+  const valueFor = (tag: string): string => {
+    switch (tag) {
+      case 'PROJEKT': return meta.project?.trim() || FALLBACK;
+      case 'DATUM': return meta.date?.trim() || FALLBACK;
+      case 'MASSSTAB': return meta.scale?.trim() || FALLBACK;
+      case 'AUTOR': return meta.author?.trim() || FALLBACK;
+      default: return FALLBACK;
+    }
+  };
+
+  for (const slot of SLOTS) {
+    els.push({
+      id: nid('attr'),
+      type: 'text',
+      layerId: 'layer-0',
+      x: -FRAME_W / 2 + slot.dx,
+      y: -FRAME_H / 2 + slot.dy,
+      width: 0,
+      height: 0,
+      properties: {
+        text: `${slot.tag}=${valueFor(slot.tag)}`,
+        fontSize: 9,
+        stroke: '#e0e0e0',
+        tag: slot.tag,
+        prompt: slot.prompt,
+        attdef: true,
+      },
+    });
+  }
+
+  return els;
+}
+
+/**
+ * Auto-insert: Erzeugt Blockdefinition + setzt frameBlockRef im Layout.
+ * Bestehende frameBlockRef wird ersetzt (Re-Insert aktualisiert Metadaten
+ * über einen neuen Block; der alte Block bleibt unreferenziert bestehen).
+ * @returns Block-ID des neuen Titelblocks.
+ * @throws wenn Layout nicht existiert.
+ */
+export function insertTitleBlockForLayout(
+  doc: CADDocument,
+  layoutId: string,
+  meta: TitleBlockMeta,
+): string {
+  const layout = doc.getLayout(layoutId);
+  if (!layout) throw new Error(`insertTitleBlockForLayout: Layout '${layoutId}' nicht gefunden`);
+
+  const blockId = nid('blk');
+  const block: BlockDefinition = {
+    id: blockId,
+    name: TITLE_BLOCK_NAME,
+    description: 'Titelblock mit Attributen (Projekt/Datum/Maßstab/Autor) — Task G3',
+    category: 'frame',
+    elements: createTitleBlockElements(meta),
+  };
+  doc.addBlock(block);
+
+  doc.updateLayout(layoutId, { frameBlockRef: blockId });
+  return blockId;
+}

frontend/src/services/uiModeService.ts

@@ -0,0 +1,66 @@
+/**
+ * Task H1 – UI-Modus simple/pro.
+ *
+ * - 'pro': vollständige Werkzeugpalette + CommandLine (Default)
+ * - 'simple': nur basic-Tools, keine CommandLine
+ *
+ * Persistenz über localStorage ('webcad.uiMode'), Subscribe-Set für
+ * Live-Updates (RibbonBar/CommandLine/Topbar hören zu). Bewusst KEIN
+ * zustand (Q2-Entscheidung wurde nie umgesetzt; Muster folgt dem
+ * etablierten documentService/featureFlags-Stil des Projekts).
+ */
+import { useEffect, useState } from 'react';
+
+export type UIMode = 'simple' | 'pro';
+
+const STORAGE_KEY = 'webcad.uiMode';
+const listeners = new Set<(mode: UIMode) => void>();
+
+function readStored(): UIMode {
+  try {
+    const raw = localStorage.getItem(STORAGE_KEY);
+    if (raw === 'simple' || raw === 'pro') return raw;
+  } catch {
+    // localStorage nicht verfügbar — Default
+  }
+  return 'pro';
+}
+
+let current: UIMode = readStored();
+
+/** Aktueller UI-Modus (Default pro, persistiert). */
+export function getUIMode(): UIMode {
+  return current;
+}
+
+/** Wechselt den Modus und persistiert. */
+export function setUIMode(mode: UIMode): void {
+  current = mode;
+  try {
+    localStorage.setItem(STORAGE_KEY, mode);
+  } catch {
+    // Persistenz optional
+  }
+  for (const cb of listeners) cb(mode);
+}
+
+/** Toggle simple ↔ pro. */
+export function toggleUIMode(): void {
+  setUIMode(current === 'pro' ? 'simple' : 'pro');
+}
+
+/** Subscribe auf Moduswechsel; gibt Unsubscribe zurück. */
+export function subscribeUIMode(cb: (mode: UIMode) => void): () => void {
+  listeners.add(cb);
+  return () => { listeners.delete(cb); };
+}
+
+/** React-Hook: aktueller Modus mit Re-Render bei Wechsel. */
+export function useUIMode(): UIMode {
+  const [mode, setMode] = useState<UIMode>(current);
+  useEffect(() => {
+    const off = subscribeUIMode(setMode);
+    return off;
+  }, []);
+  return mode;
+}

frontend/src/styles.css

@@ -2456,6 +2456,130 @@ body.drawer-open { overflow: hidden; }
   min-width: 0;
 }
 
+/* ─── Task F2: Suche, Favoriten, Thumbnail-Grid ────────── */
+.global-lib-toolbar {
+  display: flex;
+  align-items: center;
+  gap: 4px;
+  padding: 0 12px 6px;
+}
+
+.global-lib-search {
+  flex: 1;
+  min-width: 0;
+  background: var(--color-bg-secondary);
+  border: 1px solid var(--color-border);
+  color: var(--color-text);
+  font-size: 11px;
+  padding: 3px 8px;
+  border-radius: 4px;
+}
+
+.global-lib-search:focus {
+  outline: none;
+  border-color: var(--color-accent);
+}
+
+.lib-fav-section {
+  border-bottom: 1px solid var(--color-border);
+  padding-bottom: 4px;
+  margin-bottom: 4px;
+}
+
+.lib-fav-title {
+  font-size: 11px;
+  font-weight: 600;
+  color: #d9a441;
+  padding: 2px 8px;
+}
+
+.tree-fav-btn {
+  margin-left: auto;
+  background: transparent;
+  border: none;
+  color: var(--color-text-faint);
+  cursor: pointer;
+  font-size: 12px;
+  padding: 0 4px;
+  line-height: 1;
+  flex-shrink: 0;
+}
+
+.tree-fav-btn:hover { color: var(--color-text); }
+
+.tree-fav-btn.active { color: #d9a441; }
+
+.tree-thumb {
+  width: 16px;
+  height: 16px;
+  flex-shrink: 0;
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+}
+
+.tree-thumb svg {
+  width: 100%;
+  height: 100%;
+}
+
+.lib-grid {
+  display: grid;
+  grid-template-columns: repeat(auto-fill, minmax(72px, 1fr));
+  gap: 6px;
+  padding: 4px 8px;
+}
+
+.lib-grid-cell {
+  position: relative;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  gap: 2px;
+  padding: 6px 4px 4px;
+  border: 1px solid var(--color-border);
+  border-radius: 4px;
+  cursor: grab;
+  background: var(--color-bg-secondary);
+}
+
+.lib-grid-cell:hover {
+  border-color: var(--color-accent);
+  background: var(--color-bg-hover);
+}
+
+.lib-grid-cell:active { cursor: grabbing; }
+
+.lib-grid-thumb {
+  width: 36px;
+  height: 36px;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+}
+
+.lib-grid-thumb .tree-thumb {
+  width: 36px;
+  height: 36px;
+}
+
+.lib-grid-placeholder { font-size: 20px; }
+
+.lib-grid-name {
+  font-size: 10px;
+  color: var(--color-text);
+  max-width: 100%;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.lib-grid-cell .tree-fav-btn {
+  position: absolute;
+  top: 2px;
+  right: 2px;
+}
+
 /* ─── Context Menu ─────────────────────────────────────── */
 .context-menu {
   background: var(--color-bg-secondary);
@@ -2672,3 +2796,181 @@ body.drawer-open { overflow: hidden; }
   background: var(--color-accent);
   opacity: 0.7;
 }
+
+
+/* ─── Task F4 – LibraryProviderPanel ─── */
+.lib-provider-panel {
+  display: flex;
+  flex-direction: column;
+  gap: 8px;
+  padding: 8px 0 4px;
+  border-top: 1px solid rgba(255, 255, 255, 0.08);
+}
+.lprov-section { display: flex; flex-direction: column; gap: 4px; }
+.lprov-title {
+  font-size: 11px;
+  font-weight: 600;
+  color: #9aa0a6;
+  text-transform: uppercase;
+  letter-spacing: 0.04em;
+  padding: 2px 8px;
+}
+.lprov-grid {
+  display: grid;
+  grid-template-columns: repeat(auto-fill, minmax(56px, 1fr));
+  gap: 6px;
+  padding: 0 8px;
+}
+.lprov-block {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  padding: 6px 4px;
+  background: transparent;
+  border: 1px solid transparent;
+  border-radius: 6px;
+  cursor: grab;
+  color: inherit;
+  min-height: 44px;
+}
+.lprov-block:hover { background: rgba(255, 255, 255, 0.06); border-color: rgba(255, 255, 255, 0.12); }
+.lprov-block .tree-thumb svg { width: 44px; height: 36px; display: block; }
+
+
+/* ─── Task G2 – LayoutBar ─── */
+.layout-bar {
+  display: flex;
+  flex-direction: column;
+  gap: 4px;
+  padding: 6px 10px;
+  border-top: 1px solid rgba(255, 255, 255, 0.08);
+  background: rgba(20, 22, 26, 0.6);
+  max-height: 180px;
+  overflow-y: auto;
+}
+.layout-bar-header {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+}
+.layout-bar-title {
+  font-size: 11px;
+  font-weight: 600;
+  color: #9aa0a6;
+  text-transform: uppercase;
+  letter-spacing: 0.04em;
+}
+.layout-bar-add {
+  background: transparent;
+  color: #4a90d9;
+  border: 1px solid rgba(74, 144, 217, 0.4);
+  border-radius: 4px;
+  width: 22px;
+  height: 22px;
+  cursor: pointer;
+  font-size: 14px;
+  line-height: 1;
+}
+.layout-bar-add:disabled { opacity: 0.4; cursor: default; }
+.layout-bar-add:not(:disabled):hover { background: rgba(74, 144, 217, 0.15); }
+.layout-bar-empty {
+  font-size: 11px;
+  color: #6b7280;
+  padding: 4px 0;
+}
+.layout-bar-list {
+  display: flex;
+  gap: 8px;
+  overflow-x: auto;
+  padding: 2px 0 4px;
+}
+.layout-bar-item {
+  display: flex;
+  align-items: flex-start;
+  gap: 2px;
+}
+.layout-bar-entry {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  gap: 2px;
+  background: transparent;
+  border: 1px solid transparent;
+  border-radius: 6px;
+  padding: 4px;
+  cursor: pointer;
+  color: inherit;
+}
+.layout-bar-entry:hover { background: rgba(255, 255, 255, 0.06); border-color: rgba(255, 255, 255, 0.12); }
+.layout-minimap { border-radius: 4px; background: rgba(0, 0, 0, 0.25); }
+.layout-bar-name { font-size: 10px; color: #9aa0a6; }
+.layout-bar-del {
+  background: transparent;
+  border: none;
+  color: #6b7280;
+  cursor: pointer;
+  font-size: 11px;
+  padding: 2px;
+  border-radius: 4px;
+}
+.layout-bar-del:hover { color: #c0392b; background: rgba(192, 57, 43, 0.15); }
+
+.layout-bar-tb {
+  background: transparent;
+  border: none;
+  color: #6b7280;
+  cursor: pointer;
+  font-size: 11px;
+  padding: 2px;
+  border-radius: 4px;
+}
+.layout-bar-tb:hover { color: #4a90d9; background: rgba(74, 144, 217, 0.15); }
+
+
+/* ═══════════════════════════════════════════════════════════
+   Task G5 – Browser-Print: @media print zeigt nur den Druckbereich
+   ═══════════════════════════════════════════════════════════ */
+@media print {
+  @page {
+    size: A4 landscape;
+    margin: 10mm;
+  }
+
+  /* UI-Chrome im Druck ausblenden */
+  .screen-only {
+    display: none !important;
+  }
+
+  /* Druckbereich füllt die Seite */
+  .print-area {
+    width: 100% !important;
+    height: auto !important;
+    overflow: visible !important;
+    margin: 0 !important;
+    padding: 0 !important;
+    border: none !important;
+  }
+
+  /* Farben/Linien so drucken wie angezeigt */
+  .print-layout * {
+    -webkit-print-color-adjust: exact !important;
+    print-color-adjust: exact !important;
+  }
+
+  /* Body: kein Scroll, weiße Fläche */
+  body {
+    background: #fff !important;
+    overflow: hidden !important;
+  }
+}
+
+.layout-bar-print {
+  background: transparent;
+  color: #6b7280;
+  border: none;
+  cursor: pointer;
+  font-size: 13px;
+  padding: 2px 4px;
+  border-radius: 4px;
+}
+.layout-bar-print:hover { color: #4a90d9; background: rgba(74, 144, 217, 0.15); }

frontend/src/tools/modification/geometry.ts

@@ -163,7 +163,14 @@ export function mirrorElement(el: CADElement, x1: number, y1: number, x2: number
  * Offset element by a distance (creates a parallel copy).
  * For lines: offset perpendicular. For circles/arcs: adjust radius.
  */
-export function offsetElement(el: CADElement, distance: number): CADElement {
+/**
+ * Versetzt ein Element senkrecht zur seiner Richtung.
+ * @param distance positiver Betrag des Versatzes
+ * @param side 1 = links der Laufrichtung (Standard), -1 = rechts —
+ *              bei circle/arc: 1 = Radius vergrößern, -1 = verkleinern
+ */
+export function offsetElement(el: CADElement, distance: number, side?: 1 | -1): CADElement {
+  const signed = distance * (side ?? 1);
   const props = { ...el.properties };
 
   if (el.type === 'line' && props.x1 !== undefined && props.y1 !== undefined && props.x2 !== undefined && props.y2 !== undefined) {
@@ -174,8 +181,8 @@ export function offsetElement(el: CADElement, distance: number): CADElement {
     // Perpendicular unit vector
     const nx = -dy / len;
     const ny = dx / len;
-    const ox = nx * distance;
-    const oy = ny * distance;
+    const ox = nx * signed;
+    const oy = ny * signed;
     props.x1 += ox;
     props.y1 += oy;
     props.x2 += ox;
@@ -184,7 +191,7 @@ export function offsetElement(el: CADElement, distance: number): CADElement {
   }
 
   if ((el.type === 'circle' || el.type === 'arc') && props.radius !== undefined) {
-    props.radius = Math.abs(props.radius + distance);
+    props.radius = Math.abs(props.radius + signed);
     const d = props.radius * 2;
     return { ...el, width: d, height: d, properties: props };
   }
@@ -201,7 +208,7 @@ export function offsetElement(el: CADElement, distance: number): CADElement {
       if (len === 0) return p;
       const nx = -dy / len;
       const ny = dx / len;
-      return { x: p.x + nx * distance, y: p.y + ny * distance };
+      return { x: p.x + nx * signed, y: p.y + ny * signed };
     });
     return { ...el, properties: props };
   }
@@ -215,7 +222,15 @@ export function offsetElement(el: CADElement, distance: number): CADElement {
  */
 export function trimElement(el: CADElement, boundary: CADElement): CADElement | null {
   // Simplified: find intersection with boundary, trim line to that point
-  if (el.type !== 'line' || !el.properties.x1 || !el.properties.x2) return null;
+  // Hinweis: explizit auf undefined prüfen — Koordinate 0 ist gültig (nicht falsy behandeln)
+  const p = el.properties;
+  if (
+    el.type !== 'line' ||
+    p.x1 === undefined || p.y1 === undefined ||
+    p.x2 === undefined || p.y2 === undefined
+  ) {
+    return null;
+  }
 
   const intersect = findIntersection(el, boundary);
   if (!intersect) return null;
@@ -247,10 +262,60 @@ export function trimElement(el: CADElement, boundary: CADElement): CADElement |
  * Currently supports extending lines to a boundary intersection.
  */
 export function extendElement(el: CADElement, boundary: CADElement): CADElement | null {
-  if (el.type !== 'line' || !el.properties.x1 || !el.properties.x2) return null;
+  // Explizit auf undefined prüfen — Koordinate 0 ist gültig (nicht falsy behandeln)
+  const p = el.properties;
+  if (
+    el.type !== 'line' ||
+    p.x1 === undefined || p.y1 === undefined ||
+    p.x2 === undefined || p.y2 === undefined
+  ) {
+    return null;
+  }
 
-  const intersect = findIntersection(el, boundary);
-  if (!intersect) return null;
+  let intersect = findIntersection(el, boundary);
+
+  // Echtes CAD-Extend (Fallback): Wenn die Strecke die Kante NICHT berührt,
+  // suche Schnitte auf der VERLÄNGERUNG der Linie in Richtung des nahen Endes.
+  if (!intersect) {
+    const c = { x: boundary.x, y: boundary.y };
+    const r =
+      boundary.type === 'circle' || boundary.type === 'arc'
+        ? ((boundary.properties?.radius as number | undefined) ?? boundary.width / 2)
+        : null;
+    if (r === null) return null; // nur Kreis/Bogen-Kanten erweiterbar
+
+    const candidates = lineCircleIntersectionsInfinite(
+      { x: p.x1!, y: p.y1! },
+      { x: p.x2!, y: p.y2! },
+      c,
+      r as number,
+    );
+    if (candidates.length === 0) return null;
+
+    // Wähle den Schnittpunkt, der an der Seite des NÄHEREN Endes liegt:
+    // Erst feststellen, welches Ende näher am Kreiszentrum liegt → dieses wird gestreckt.
+    const d1 = Math.hypot(p.x1! - c.x, p.y1! - c.y);
+    const d2 = Math.hypot(p.x2! - c.x, p.y2! - c.y);
+    const nearerIsStart = d1 <= d2;
+    const anchor = nearerIsStart ? { x: p.x1!, y: p.y1! } : { x: p.x2!, y: p.y2! };
+    intersect = candidates.reduce((best, cur) =>
+      Math.hypot(cur.x - anchor.x, cur.y - anchor.y) < Math.hypot(best.x - anchor.x, best.y - anchor.y) ? cur : best,
+    );
+
+    // Neu berechnete bbox/center auf Basis der Länge nach dem Strekken:
+    const nx1 = nearerIsStart ? intersect.x : p.x1!;
+    const ny1 = nearerIsStart ? intersect.y : p.y1!;
+    const nx2 = nearerIsStart ? p.x2! : intersect.x;
+    const ny2 = nearerIsStart ? p.y2! : intersect.y;
+    return {
+      ...el,
+      x: (nx1 + nx2) / 2,
+      y: (ny1 + ny2) / 2,
+      width: Math.abs(nx2 - nx1),
+      height: Math.abs(ny2 - ny1),
+      properties: { ...p, x1: nx1, y1: ny1, x2: nx2, y2: ny2 },
+    };
+  }
 
   const props = { ...el.properties };
   // Extend the end that is closer to the intersection
@@ -300,22 +365,197 @@ export function filletElements(el1: CADElement, el2: CADElement, radius: number)
 /**
  * Find intersection point of two elements (lines only for now).
  */
-function findIntersection(el1: CADElement, el2: CADElement): { x: number; y: number } | null {
+/** Punkt im 2D-Raum. */
+export interface Pt {
+  x: number;
+  y: number;
+}
+
+/**
+ * Alle Schnittpunkte einer Strecke p1→p2 mit einem Kreis (Zentrum c, Radius r).
+ * Liefert nur Punkte innerhalb des Streckensegments (t ∈ [0,1]); [] wenn keine.
+ */
+export function lineCircleIntersections(p1: Pt, p2: Pt, c: Pt, r: number): Pt[] {
+  const dx = p2.x - p1.x;
+  const dy = p2.y - p1.y;
+  const fx = p1.x - c.x;
+  const fy = p1.y - c.y;
+
+  const a = dx * dx + dy * dy;
+  const b = 2 * (fx * dx + fy * dy);
+  const cc = fx * fx + fy * fy - r * r;
+
+  let discriminant = b * b - 4 * a * cc;
+  if (discriminant < 0) return []; // keine reale Lösung
+
+  discriminant = Math.sqrt(discriminant);
+  const t1 = (-b - discriminant) / (2 * a);
+  const t2 = (-b + discriminant) / (2 * a);
+  // Tangente: beide Lösungen identisch → nur einen Punkt liefern
+  const ts = Math.abs(t1 - t2) < 1e-7 ? [t1] : [t1, t2];
+  const eps = 1e-9;
+  const results: Pt[] = [];
+  for (const t of ts) {
+    if (t >= -eps && t <= 1 + eps) {
+      results.push({ x: p1.x + t * dx, y: p1.y + t * dy });
+    }
+  }
+  return results;
+}
+
+/**
+ * Schnittpunkte zweier Kreise (Zentren c1/c2, Radien r1/r2).
+ * Liefert 0–2 Punkte; [] wenn getrennt oder identisch.
+ */
+export function circleCircleIntersections(c1: Pt, r1: number, c2: Pt, r2: number): Pt[] {
+  const dVec = { x: c2.x - c1.x, y: c2.y - c1.y };
+  const d = Math.hypot(dVec.x, dVec.y);
+  if (d === 0) return [];                       // identische Zentren
+  if (d > r1 + r2 || d < Math.abs(r1 - r2)) return []; // getrennt / ineinander
+
+  const a = (r1 * r1 - r2 * r2 + d * d) / (2 * d);
+  const hSq = r1 * r1 - a * a;
+  const h = Math.sqrt(Math.max(0, hSq));
+  const baseX = c1.x + (a * dVec.x) / d;
+  const baseY = c1.y + (a * dVec.y) / d;
+  if (h === 0) return [{ x: baseX, y: baseY }];  // tangentiale Berührung
+  return [
+    { x: baseX + (h * dVec.y) / d, y: baseY - (h * dVec.x) / d },
+    { x: baseX - (h * dVec.y) / d, y: baseY + (h * dVec.x) / d },
+  ];
+}
+
+/**
+ * Liest die Arc-Parameter eines CADElements nach der Konvention von
+ * RenderEngine.drawArc: Zentrum = el.x/el.y, radius/startAngle/endAngle aus
+ * properties; Winkel in GRAD, 0° = 3 Uhr, gegen Uhrzeigersinn.
+ */
+function readArc(el: CADElement): { c: Pt; r: number; startDeg: number; endDeg: number } | null {
+  const r = (el.properties?.radius as number | undefined) ?? (el as unknown as { width?: number }).width! / 2;
+  if (!Number.isFinite(r) || r <= 0) return null;
+  return {
+    c: { x: el.x, y: el.y },
+    r,
+    startDeg: ((el.properties?.startAngle as number | undefined) ?? 0),
+    endDeg: ((el.properties?.endAngle as number | undefined) ?? 360),
+  };
+}
+
+/** Prüft, ob ein Winkel (Grad) innerhalb eines Bogens liegt (CCW von start bis end). */
+function angleInArcRange(deg: number, startDeg: number, endDeg: number): boolean {
+  const norm = (v: number) => ((v % 360) + 360) % 360;
+  let a = norm(deg);
+  const s = norm(startDeg);
+  const e = norm(endDeg);
+  if (s <= e) return a >= s && a <= e;
+  return a >= s || a <= e; // Bogen über 0°
+}
+
+/**
+ * Wie lineCircleIntersections, aber OHNE Segmentbegrenzung (t ∈ ℝ):
+ * findet Schnitte auch auf der VERLÄNGERUNG der Strecke — Grundlage für
+ * echtes CAD-Extend (Task A4.10), bei dem das Ziel die Kante oft noch
+ * gar nicht berührt.
+ */
+export function lineCircleIntersectionsInfinite(p1: Pt, p2: Pt, c: Pt, r: number): Pt[] {
+  const dx = p2.x - p1.x;
+  const dy = p2.y - p1.y;
+  const fx = p1.x - c.x;
+  const fy = p1.y - c.y;
+  const a = dx * dx + dy * dy;
+  if (a < 1e-12) return [];
+  const b = 2 * (fx * dx + fy * dy);
+  const cc = fx * fx + fy * fy - r * r;
+  let disc = b * b - 4 * a * cc;
+  if (disc < 0) return [];
+  disc = Math.sqrt(disc);
+  const out: Pt[] = [];
+  for (const t of [(-b - disc) / (2 * a), (-b + disc) / (2 * a)]) {
+    out.push({ x: p1.x + t * dx, y: p1.y + t * dy });
+  }
+  return out;
+}
+
+/**
+ * Alle Schnittpunkte einer Strecke p1→p2 mit dem Bogen eines Elements
+ * (Konvention wie RenderEngine.drawArc). Nur Treffer innerhalb des Segments
+ * UND im Winkelbereich des Bogens werden zurückgegeben.
+ */
+export function lineArcIntersection(p1: Pt, p2: Pt, el: CADElement): Pt[] {
+  const arc = readArc(el);
+  if (!arc) return [];
+  return lineCircleIntersections(p1, p2, arc.c, arc.r)
+    .filter((pt) => angleInArcRange((Math.atan2(pt.y - arc.c.y, pt.x - arc.c.x) * 180) / Math.PI, arc.startDeg, arc.endDeg));
+}
+
+function lineLineIntersections(el1: CADElement, el2: CADElement): Pt[] {
   const p1 = el1.properties;
   const p2 = el2.properties;
 
-  if (p1.x1 === undefined || p1.y1 === undefined || p1.x2 === undefined || p1.y2 === undefined) return null;
-  if (p2.x1 === undefined || p2.y1 === undefined || p2.x2 === undefined || p2.y2 === undefined) return null;
+  if (p1.x1 === undefined || p1.y1 === undefined || p1.x2 === undefined || p1.y2 === undefined) return [];
+  if (p2.x1 === undefined || p2.y1 === undefined || p2.x2 === undefined || p2.y2 === undefined) return [];
 
-  // Line-line intersection
-  const denom = (p1.x1 - p1.x2) * (p2.y1 - p2.y2) - (p1.y1 - p1.y2) * (p2.x1 - p2.x2);
-  if (Math.abs(denom) < 1e-10) return null;
+  const denom = (p1.x1! - p1.x2!) * (p2.y1! - p2.y2!) - (p1.y1! - p1.y2!) * (p2.x1! - p2.x2!);
+  if (Math.abs(denom) < 1e-10) return [];
 
-  const t = ((p1.x1 - p2.x1) * (p2.y1 - p2.y2) - (p1.y1 - p2.y1) * (p2.x1 - p2.x2)) / denom;
-  const x = p1.x1 + t * (p1.x2 - p1.x1);
-  const y = p1.y1 + t * (p1.y2 - p1.y1);
+  const t = ((p1.x1! - p2.x1!) * (p2.y1! - p2.y2!) - (p1.y1! - p2.y1!) * (p2.x1! - p2.x2!)) / denom;
+  const x = p1.x1! + t * (p1.x2! - p1.x1!);
+  const y = p1.y1! + t * (p1.y2! - p1.y1!);
+  return [{ x, y }];
+}
 
-  return { x, y };
+/**
+ * Erster Schnittpunkt zweier CAD-Elemente (line/circle/arc), intern für
+ * trim/extend/fillet. Bei mehreren Treffern wird der zu el1 nächstgelegene
+ * gewählt. null wenn keine Kombination unterstützt oder kein Schnitt.
+ */
+function findIntersection(el1: CADElement, el2: CADElement): { x: number; y: number } | null {
+  const types = new Set([el1.type, el2.type]);
+  // Linie immer als erstes Argument normalisieren (reihenfolgeunabhängig)
+  const [lineEl, otherEl] = el1.type === 'line' ? [el1, el2] : [el2, el1];
+  let candidates: Pt[] = [];
+  let refFromFirst = true; // Referenzpunkt von el1 nehmen?
+
+  if (types.has('line') && types.size === 1) {
+    candidates = lineLineIntersections(el1, el2);
+    refFromFirst = false; // beide sind Linien; Referenz unten via el1-Startpunkt
+  } else if (types.has('line') && types.has('circle')) {
+    candidates = lineCircleIntersections(
+      { x: lineEl.properties.x1!, y: lineEl.properties.y1! },
+      { x: lineEl.properties.x2!, y: lineEl.properties.y2! },
+      { x: otherEl.x, y: otherEl.y },
+      (otherEl.properties.radius as number | undefined) ?? otherEl.width / 2,
+    );
+  } else if (types.has('line') && types.has('arc')) {
+    candidates = lineArcIntersection(
+      { x: lineEl.properties.x1!, y: lineEl.properties.y1! },
+      { x: lineEl.properties.x2!, y: lineEl.properties.y2! },
+      otherEl,
+    );
+  } else if (types.has('circle') && types.size === 1) {
+    candidates = circleCircleIntersections(
+      { x: el1.x, y: el1.y },
+      (el1.properties.radius as number | undefined) ?? el1.width / 2,
+      { x: el2.x, y: el2.y },
+      (el2.properties.radius as number | undefined) ?? el2.width / 2,
+    );
+    refFromFirst = false;
+  }
+
+  if (candidates.length === 0) return null;
+  // Nächstliegenden Treffer zu el1 wählen (Startpunkt bei Linie, sonst Zentrum)
+  const isFirstLine = el1.type === 'line';
+  const refX = refFromFirst || isFirstLine
+    ? (isFirstLine ? el1.properties.x1 : el1.x)
+    : el1.x;
+  const refY = refFromFirst || isFirstLine
+    ? (isFirstLine ? el1.properties.y1 : el1.y)
+    : el1.y;
+  let best = candidates[0];
+  for (const c of candidates) {
+    if (Math.hypot(c.x - refX!, c.y - refY!) < Math.hypot(best.x - refX!, best.y - refY!)) best = c;
+  }
+  return best;
 }
 
 /**
@@ -348,3 +588,19 @@ export function distance(p1: { x: number; y: number }, p2: { x: number; y: numbe
 export function angleBetween(p1: { x: number; y: number }, p2: { x: number; y: number }): number {
   return (Math.atan2(p2.y - p1.y, p2.x - p1.x) * 180) / Math.PI;
 }
+
+/**
+ * Fläche eines Polygons via Shoelace-Formel (Task H5).
+ * Absolutwert — Uhrzeigersinn und gegen Uhrzeigersinn ergeben dasselbe.
+ * Weniger als 3 Punkte oder kollineare Punkte → 0.
+ */
+export function polygonArea(pts: Array<{ x: number; y: number }>): number {
+  if (!Array.isArray(pts) || pts.length < 3) return 0;
+  let sum = 0;
+  for (let i = 0; i < pts.length; i++) {
+    const a = pts[i];
+    const b = pts[(i + 1) % pts.length];
+    sum += a.x * b.y - b.x * a.y;
+  }
+  return Math.abs(sum / 2);
+}

frontend/src/types/cad.types.ts

@@ -6,7 +6,8 @@ export type ElementType =
   | 'line' | 'circle' | 'arc' | 'rect' | 'polygon'
   | 'polyline' | 'text' | 'dimension' | 'block_instance' | 'chair'
   | 'seating-row' | 'seating-block' | 'table' | 'stage'
-  | 'leader' | 'revcloud' | 'image';
+  | 'leader' | 'revcloud' | 'image'
+  | 'curtain' | 'spotlight' | 'barrier';
 
 export type LineType = 'solid' | 'dashed' | 'dotted';
 
@@ -62,6 +63,16 @@ export interface ImageElement extends CADElement {
   };
 }
 
+/**
+ * Block-Attribut-Definition (Task D12): Slot, den Instanzen befüllen.
+ * Konvention konsistent zu F5 (ATTDEF-Parser) und F6 (DXF-Writer).
+ */
+export interface BlockAttrDef {
+  tag: string;
+  prompt: string;
+  defaultValue?: string;
+}
+
 export interface BlockDefinition {
   id: string;
   name: string;
@@ -69,6 +80,25 @@ export interface BlockDefinition {
   category: string;
   elements: CADElement[];
   thumbnail?: string;
+  /** Attribut-Slots dieser Blockdefinition (Task D12). */
+  attrDefs?: BlockAttrDef[];
+}
+
+/**
+ * Layout (Task G1): Papier-/Plot-Seite mit eigenem Viewport aufs Modell.
+ * Persistiert in der Yjs-Map 'layouts' (key = layoutId).
+ */
+export interface LayoutViewport {
+  center: { x: number; y: number };
+  scale: number;
+}
+
+export interface LayoutDefinition {
+  id: string;
+  name: string;
+  viewport: LayoutViewport;
+  /** Referenz auf den Titelblock-Block (frame block), optional. */
+  frameBlockRef?: string;
 }
 
 export interface BoundingBox {

frontend/src/types/ui.types.ts

@@ -94,6 +94,8 @@ export interface RibbonBarProps {
   onCanvasBgColorChange?: (color: string) => void;
   onGridColorChange?: (color: string) => void;
   onToggleRuler?: () => void;
+  /** Task A4.13: meldet, ob ein V2-Werkzeug-ID aktuell das aktive Tool ist (Highlight). */
+  onIsV2ToolActive?: (toolId: string) => boolean;
 }
 
 export interface LeftSidebarProps {

frontend/src/utils/blockThumbnail.ts

@@ -0,0 +1,109 @@
+/**
+ * blockThumbnail – SVG-Thumbnail-Generierung für Block-Bibliothek (Task F3).
+ *
+ * Statt canvas.toDataURL werden die Elemente über die bereits vorhandene,
+ * testbare Shape-Fabrik elementToPrimitives (Task C2) beschrieben und als
+ * eigenständiges SVG serialisiert. Vorteile:
+ * - Konsistent zu den svg_data-Thumbnails der globalen Bibliothek (Tree/Grid)
+ * - Unit-testbar ohne Canvas/DOM
+ * - Skalierbar & themefarben-identisch zur Zeichenfläche
+ *
+ * BBox-Konvention wie elementDrawers: rect x/y = Zentrum der BBox,
+ * circle/arc radius via center ± r.
+ */
+import { elementToPrimitives } from '../render/pixi/elementDrawers';
+import type { ShapePrimitive } from '../render/pixi/elementDrawers';
+import type { CADElement } from '../types/cad.types';
+
+const PAD = 10;
+
+function fmt(n: number): string {
+  return String(Math.round(n * 100) / 100);
+}
+
+function escapeXml(s: string): string {
+  return s.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;');
+}
+
+interface BBox { minX: number; minY: number; maxX: number; maxY: number }
+
+function primExtent(p: ShapePrimitive, acc: BBox): void {
+  const add = (x: number, y: number) => {
+    if (x < acc.minX) acc.minX = x;
+    if (y < acc.minY) acc.minY = y;
+    if (x > acc.maxX) acc.maxX = x;
+    if (y > acc.maxY) acc.maxY = y;
+  };
+  switch (p.kind) {
+    case 'line':
+      add(p.from.x, p.from.y); add(p.to.x, p.to.y);
+      break;
+    case 'rect':
+      add(p.x - p.w / 2, p.y - p.h / 2); add(p.x + p.w / 2, p.y + p.h / 2);
+      break;
+    case 'circle':
+      add(p.center.x - p.radius, p.center.y - p.radius); add(p.center.x + p.radius, p.center.y + p.radius);
+      break;
+    case 'arc':
+      add(p.center.x - p.radius, p.center.y - p.radius); add(p.center.x + p.radius, p.center.y + p.radius);
+      break;
+    case 'polyline':
+      for (const pt of p.points) add(pt.x, pt.y);
+      break;
+    case 'text':
+      add(p.at.x, p.at.y - p.fontSize);
+      add(p.at.x + p.fontSize * 0.6 * p.text.length, p.at.y);
+      break;
+  }
+}
+
+function primToSvgTag(p: ShapePrimitive): string {
+  switch (p.kind) {
+    case 'line':
+      return `<line x1="${fmt(p.from.x)}" y1="${fmt(p.from.y)}" x2="${fmt(p.to.x)}" y2="${fmt(p.to.y)}" stroke="${p.stroke}" stroke-width="${p.strokeWidth}"/>`;
+    case 'rect':
+      return `<rect x="${fmt(p.x - p.w / 2)}" y="${fmt(p.y - p.h / 2)}" width="${fmt(p.w)}" height="${fmt(p.h)}" fill="${p.fill ?? 'none'}" stroke="${p.stroke}" stroke-width="${p.strokeWidth}"/>`;
+    case 'circle':
+      return `<circle cx="${fmt(p.center.x)}" cy="${fmt(p.center.y)}" r="${fmt(p.radius)}" fill="${p.fill ?? 'none'}" stroke="${p.stroke}" stroke-width="${p.strokeWidth}"/>`;
+    case 'arc': {
+      // Konvention: 0° = 3 Uhr, gegen Uhrzeigersinn (Bildschirm-Y zeigt nach unten)
+      const rad = (deg: number) => (deg * Math.PI) / 180;
+      const sx = p.center.x + p.radius * Math.cos(rad(p.startDeg));
+      const sy = p.center.y - p.radius * Math.sin(rad(p.startDeg));
+      const ex = p.center.x + p.radius * Math.cos(rad(p.endDeg));
+      const ey = p.center.y - p.radius * Math.sin(rad(p.endDeg));
+      let delta = (p.endDeg - p.startDeg) % 360;
+      if (delta < 0) delta += 360;
+      const largeArc = delta > 180 ? 1 : 0;
+      // CCW auf dem Schirm = SVG sweep-flag 0
+      return `<path d="M ${fmt(sx)} ${fmt(sy)} A ${fmt(p.radius)} ${fmt(p.radius)} 0 ${largeArc} 0 ${fmt(ex)} ${fmt(ey)}" fill="none" stroke="${p.stroke}" stroke-width="${p.strokeWidth}"/>`;
+    }
+    case 'polyline': {
+      const pts = p.points.map(pt => `${fmt(pt.x)},${fmt(pt.y)}`).join(' ');
+      if (p.close) {
+        return `<polygon points="${pts}" fill="${'none'}" stroke="${p.stroke}" stroke-width="${p.strokeWidth}"/>`;
+      }
+      return `<polyline points="${pts}" fill="none" stroke="${p.stroke}" stroke-width="${p.strokeWidth}"/>`;
+    }
+    case 'text':
+      return `<text x="${fmt(p.at.x)}" y="${fmt(p.at.y)}" font-size="${p.fontSize}" fill="${p.color}">${escapeXml(p.text)}</text>`;
+  }
+}
+
+/** Serialisiert Primitive zu einem eigenständigen SVG-String (leer bei []). */
+export function primitivesToSvg(prims: ShapePrimitive[]): string {
+  if (prims.length === 0) return '';
+  const acc: BBox = { minX: Infinity, minY: Infinity, maxX: -Infinity, maxY: -Infinity };
+  for (const p of prims) primExtent(p, acc);
+  const w = acc.maxX - acc.minX;
+  const h = acc.maxY - acc.minY;
+  const vb = `${fmt(acc.minX - PAD)} ${fmt(acc.minY - PAD)} ${fmt(w + 2 * PAD)} ${fmt(h + 2 * PAD)}`;
+  const body = prims.map(primToSvgTag).join('');
+  return `<svg xmlns="http://www.w3.org/2000/svg" viewBox="${vb}">${body}</svg>`;
+}
+
+/** Erzeugt ein SVG-Thumbnail aus einer Element-Auswahl (Task F3). */
+export function generateBlockSvg(elements: CADElement[]): string {
+  const prims = elements.flatMap(el => elementToPrimitives(el));
+  return primitivesToSvg(prims);
+}

frontend/src/utils/format.ts

@@ -92,3 +92,28 @@ export function formatInputValue(
       return `${(mm / 1000).toFixed(3)}`;
   }
 }
+
+/**
+ * Format a raw world-unit squared area value (Task H5).
+ * @param rawSquared squared world-units (e.g. polygonArea result)
+ * @param unit target display unit
+ * @param scaleFactor world-units → mm conversion (like formatDistance)
+ * @returns formatted string like "5000 mm²", "50.0 cm²", "5.00 m²"
+ */
+export function formatArea(
+  rawSquared: number,
+  unit: UnitType,
+  scaleFactor: number = 1,
+): string {
+  const mmSquared = rawSquared * scaleFactor * scaleFactor;
+  switch (unit) {
+    case 'mm':
+      return `${mmSquared.toFixed(0)} mm²`;
+    case 'cm':
+      return `${(mmSquared / 100).toFixed(1)} cm²`;
+    case 'm':
+      return `${(mmSquared / 1000000).toFixed(2)} m²`;
+    default:
+      return `${mmSquared.toFixed(0)} mm²`;
+  }
+}

frontend/src/utils/logger.ts

@@ -0,0 +1,69 @@
+/**
+ * Minimaler Level-basierter Logger.
+ * Ziel: direktes `console.log` im Produktivcode ersetzen (ROADMAP Teil-4-Regel),
+ * damit sich Logs zentral filtern/abschalten lassen.
+ *
+ * Nutzung:
+ *   import { logger } from '../utils/logger';
+ *   logger.info('Element erstellt', el.id);
+ *
+ * Level über localStorage['webcad.logLevel'] ('silent'|'error'|'warn'|'info'|'debug',
+ * Default: 'info'). `logger.debug` bleibt auf Default still.
+ */
+
+export type LogLevel = 'silent' | 'error' | 'warn' | 'info' | 'debug';
+
+const LEVEL_ORDER: Record<LogLevel, number> = {
+  silent: 100,
+  error: 40,
+  warn: 30,
+  info: 20,
+  debug: 10,
+};
+
+function readConfiguredLevel(): LogLevel {
+  try {
+    // Browser und jsdom haben localStorage; in reinen Node-Tests schlägt der Zugriff fehl
+    const raw = globalThis.localStorage?.getItem('webcad.logLevel');
+    if (raw && raw in LEVEL_ORDER) return raw as LogLevel;
+  } catch {
+    /* Umgebung ohne localStorage → Default */
+  }
+  return 'info';
+}
+
+let currentLevel: LogLevel = readConfiguredLevel();
+
+/** Setzt das Level programmatisch (überschreibt localStorage bis zum Reload). */
+export function setLogLevel(level: LogLevel): void {
+  currentLevel = level;
+}
+
+/** Aktuell aktives Log-Level. */
+export function getLogLevel(): LogLevel {
+  return currentLevel;
+}
+
+class Logger {
+  /** Fehlerhafte Zustände — melden außer bei silent. */
+  error(...args: unknown[]): void {
+    if (LEVEL_ORDER[currentLevel] <= LEVEL_ORDER.error) console.error('[web-cad]', ...args);
+  }
+
+  /** Warnungen. */
+  warn(...args: unknown[]): void {
+    if (LEVEL_ORDER[currentLevel] <= LEVEL_ORDER.warn) console.warn('[web-cad]', ...args);
+  }
+
+  /** Normale Informationsmeldungen (Default-Level aktiv). */
+  info(...args: unknown[]): void {
+    if (LEVEL_ORDER[currentLevel] <= LEVEL_ORDER.info) console.log('[web-cad]', ...args);
+  }
+
+  /** Debug-Ausgaben — nur wenn Level debug konfiguriert ist. */
+  debug(...args: unknown[]): void {
+    if (LEVEL_ORDER[currentLevel] <= LEVEL_ORDER.debug) console.log('[web-cad][debug]', ...args);
+  }
+}
+
+export const logger = new Logger();

frontend/tests/arrayPath.test.ts

@@ -0,0 +1,170 @@
+/**
+ * Task D10-Rest – array-path: Elemente entlang einer Polyline verteilen.
+ *
+ * Klick1 = Quelle (Auto-HitSelect bei leerer Selektion), Klick2 auf
+ * Pfad-Polyline → Element-Kopien gleichmaessig entlang der Pfad-
+ * laenge verteilt (count aus Options, Default 5), Original bleibt,
+ * ALLES in EINER Transaktion = 1 Undo-Schritt.
+ */
+import { describe, it, expect, beforeEach } from 'vitest';
+import { arrayPathTool } from '../src/plugins/builtin/core-modify';
+import { CADDocument } from '../src/kernel/document/CADDocument';
+import { createInMemoryDoc } from './helpers/inMemoryDoc';
+import type { CADElement, Pt } from '../src/types/cad.types';
+
+function mkCtx(elements: CADElement[], options: Record<string, unknown> = {}) {
+  const { ydoc } = createInMemoryDoc();
+  const doc = new CADDocument(ydoc);
+  for (const el of elements) doc.addElement(el);
+  const selectedIds = new Set<string>();
+  const statuses: string[] = [];
+  const ctx: any = {
+    doc,
+    options,
+    setStatus: (m: string) => statuses.push(m),
+    setPreview: (_el: CADElement | null) => {},
+    selection: {
+      getIds: () => Array.from(selectedIds),
+      setIds: (ids: string[]) => {
+        selectedIds.clear();
+        for (const id of ids) selectedIds.add(id);
+      },
+      hitTest: (x: number, y: number, _tol: number) => {
+        // trifft das Element, dessen BBox den Punkt enthaelt (erstes Gewinnt)
+        for (const el of elements) {
+          if (
+            x >= el.x - el.width / 2 && x <= el.x + el.width / 2 &&
+            y >= el.y - el.height / 2 && y <= el.y + el.height / 2
+          ) return el;
+        }
+        return null;
+      },
+    },
+  };
+  return { ctx, doc, selectedIds, statuses };
+}
+
+function pe(x: number, y: number): { world: Pt } {
+  return { world: { x, y } } as never;
+}
+
+const CHAIR = {
+  id: 'chair-1', type: 'chair', layerId: 'layer-0',
+  x: 0, y: 0, width: 40, height: 40, properties: {},
+} as unknown as CADElement;
+
+const PATH = {
+  id: 'path-1', type: 'polyline', layerId: 'layer-0',
+  x: 250, y: 0, width: 500, height: 0,
+  properties: { points: [{ x: 0, y: 0 }, { x: 500, y: 0 }] },
+} as unknown as CADElement;
+
+beforeEach(() => {
+  arrayPathTool.handlers.cancel?.({ setStatus: () => {}, setPreview: () => {} } as never);
+});
+
+describe('D10: arrayPathTool', () => {
+  it('verteilt count Kopien gleichmaessig entlang der Pfadlaenge (Original bleibt)', () => {
+    const { ctx, doc, selectedIds } = mkCtx([CHAIR, PATH]);
+    selectedIds.add('chair-1');
+    // Klick1: Quelle ist schon selektiert -> Basis direkt setzen
+    arrayPathTool.handlers.down!(pe(0, 0), ctx);
+    // Klick2: auf den Pfad klicken (Pfad-Mitte 250,0)
+    arrayPathTool.handlers.down!(pe(250, 0), ctx);
+
+    const els = doc.getAllElements();
+    // Original + Pfad + 5 Kopien
+    const chairs = els.filter((e) => e.type === 'chair');
+    expect(chairs.length).toBe(1 + 5);
+    // Kopien getrennt vom Original (Original bleibt bei x=0 unangetastet):
+    const copies = chairs.filter((c) => c.id !== 'chair-1');
+    expect(copies).toHaveLength(5);
+    const copyXs = copies.map((c) => c.x).sort((a, b) => a - b);
+    // count=5 gleichmaessig ueber Pfadlaenge 500: s = i/(count-1)*total
+    expect(copyXs[0]).toBeCloseTo(0, 0);
+    expect(copyXs[1]).toBeCloseTo(125, 0);
+    expect(copyXs[2]).toBeCloseTo(250, 0);
+    expect(copyXs[3]).toBeCloseTo(375, 0);
+    expect(copyXs[4]).toBeCloseTo(500, 0);
+  });
+
+  it('Auto-HitSelect bei leerer Selektion (Klick1 auf Element)', () => {
+    const { ctx, doc, selectedIds } = mkCtx([CHAIR, PATH]);
+    // Selektion ist leer: Klick auf den Stuhl waehlt ihn automatisch
+    arrayPathTool.handlers.down!(pe(0, 0), ctx);
+    expect(selectedIds.has('chair-1')).toBe(true);
+    // Klick2 auf Pfad -> Commit
+    arrayPathTool.handlers.down!(pe(100, 0), ctx);
+    expect(doc.getAllElements().filter((e) => e.type === 'chair').length).toBe(6);
+  });
+
+  it('Klick2 trifft KEINEN Pfad -> kein Commit, Status erklaert', () => {
+    const { ctx, doc, selectedIds, statuses } = mkCtx([CHAIR, PATH]);
+    selectedIds.add('chair-1');
+    arrayPathTool.handlers.down!(pe(0, 0), ctx);
+    // Klick weit weg vom Pfad (kein Element getroffen)
+    arrayPathTool.handlers.down!(pe(9999, 9999), ctx);
+    expect(doc.getAllElements().filter((e) => e.type === 'chair')).toHaveLength(1);
+    expect(statuses[statuses.length - 1]).toContain('Pfad');
+  });
+
+  it('Kopien in EINER Transaktion = 1 Undo entfernt alle', () => {
+    const { ctx, doc, selectedIds } = mkCtx([CHAIR, PATH]);
+    selectedIds.add('chair-1');
+    arrayPathTool.handlers.down!(pe(0, 0), ctx);
+    arrayPathTool.handlers.down!(pe(250, 0), ctx);
+    expect(doc.getAllElements().filter((e) => e.type === 'chair')).toHaveLength(6);
+    doc.undo();
+    expect(doc.getAllElements().filter((e) => e.type === 'chair')).toHaveLength(1);
+  });
+
+  it('count-Option steuert die Anzahl (3 statt 5)', () => {
+    const { ctx, doc, selectedIds } = mkCtx([CHAIR, PATH], { count: 3 });
+    selectedIds.add('chair-1');
+    arrayPathTool.handlers.down!(pe(0, 0), ctx);
+    arrayPathTool.handlers.down!(pe(250, 0), ctx);
+    expect(doc.getAllElements().filter((e) => e.type === 'chair')).toHaveLength(4); // Original + 3
+    // Kopien getrennt vom Original: count=3 -> s = 0, 250, 500
+    const copies3 = doc.getAllElements().filter((e) => e.type === 'chair' && e.id !== 'chair-1');
+    const copyXs3 = copies3.map((c) => c.x).sort((a, b) => a - b);
+    expect(copyXs3[0]).toBeCloseTo(0, 0);
+    expect(copyXs3[1]).toBeCloseTo(250, 0);
+    expect(copyXs3[2]).toBeCloseTo(500, 0);
+  });
+
+  it('gebogener Pfad (3 Punkte): Kopien folgen der Geometrie', () => {
+    const cornerPath = {
+      id: 'path-2', type: 'polyline', layerId: 'layer-0',
+      x: 100, y: 100, width: 200, height: 200,
+      properties: { points: [{ x: 0, y: 0 }, { x: 200, y: 0 }, { x: 200, y: 200 }] },
+    } as unknown as CADElement;
+    const { ctx, doc, selectedIds } = mkCtx([CHAIR, cornerPath], { count: 4 });
+    selectedIds.add('chair-1');
+    arrayPathTool.handlers.down!(pe(0, 0), ctx);
+    arrayPathTool.handlers.down!(pe(100, 10), ctx);
+    const chairs = doc.getAllElements().filter((e) => e.type === 'chair');
+    expect(chairs.length).toBe(5); // Original + 4
+    // Kopien muessen auf dem L-foermigen Pfad liegen: alle x<=200, y>=0
+    for (const c of chairs.slice(1)) {
+      expect(c.x).toBeLessThanOrEqual(200.5);
+      expect(c.y).toBeGreaterThanOrEqual(-0.5);
+    }
+  });
+
+  it('cancel resettet die Sitzung', () => {
+    const { ctx, doc, selectedIds } = mkCtx([CHAIR, PATH]);
+    selectedIds.add('chair-1');
+    arrayPathTool.handlers.down!(pe(0, 0), ctx);
+    arrayPathTool.handlers.cancel?.(ctx);
+    // Nach cancel: Klick startet frisch (Auto-HitSelect-Pfad wieder aktiv)
+    arrayPathTool.handlers.down!(pe(9999, 9999), ctx);
+    expect(doc.getAllElements().filter((e) => e.type === 'chair')).toHaveLength(1);
+  });
+
+  it('Manifest: id=array-path, tags pro', () => {
+    expect(arrayPathTool.manifest.id).toBe('array-path');
+    expect((arrayPathTool.manifest.tags ?? [])).toContain('pro');
+    const keys = (arrayPathTool.optionsSchema ?? []).map((f) => f.key);
+    expect(keys).toContain('count');
+  });
+});

frontend/tests/blockAttributes.test.ts

@@ -0,0 +1,104 @@
+/**
+ * Task D12 - BlockAttribute: attrDefs + attrValues + Rendering.
+ *
+ * BlockDefinition.attrDefs[]: definiert Attribut-Slots (tag/prompt/
+ * default). Instanz (block_instance) traegt attrValues. Der Render-
+ * Adapter (elementToPrimitives) zeichnet die Attr-Werte als Text-
+ * Primitive an der Instanz-Position.
+ */
+import { describe, it, expect } from 'vitest';
+import { CADDocument } from '../src/kernel/document/CADDocument';
+import { createInMemoryDoc } from './helpers/inMemoryDoc';
+import { elementToPrimitives } from '../src/render/pixi/elementDrawers';
+import type { CADElement, BlockDefinition } from '../src/types/cad.types';
+
+const BLOCK: BlockDefinition = {
+  id: 'blk-1',
+  name: 'Titelblock',
+  description: '',
+  category: 'frame',
+  elements: [],
+  attrDefs: [
+    { tag: 'PROJEKT', prompt: 'Projektname', defaultValue: 'Unbenannt' },
+    { tag: 'AUTOR', prompt: 'Bearbeiter', defaultValue: 'WebCAD' },
+  ],
+};
+
+function instance(attrValues: Record<string, string>): CADElement {
+  return {
+    id: 'inst-1', type: 'block_instance', layerId: 'layer-0',
+    x: 100, y: 100, width: 0, height: 0,
+    properties: { blockId: 'blk-1', scale: 1, attrValues },
+  } as unknown as CADElement;
+}
+
+// ─── Typ-Ebene: attrDefs auf BlockDefinition ────────────────
+
+describe('D12: BlockDefinition.attrDefs', () => {
+  it('attrDefs-Feld existiert mit tag/prompt/defaultValue', () => {
+    expect(BLOCK.attrDefs).toBeDefined();
+    expect(BLOCK.attrDefs!.length).toBe(2);
+    expect(BLOCK.attrDefs![0].tag).toBe('PROJEKT');
+    expect(BLOCK.attrDefs![0].prompt).toBe('Projektname');
+    expect(BLOCK.attrDefs![0].defaultValue).toBe('Unbenannt');
+  });
+
+  it('CADDocument speichert Block mit attrDefs (getBlock liefert sie zurueck)', () => {
+    const { ydoc } = createInMemoryDoc();
+    const doc = new CADDocument(ydoc);
+    doc.addBlock(BLOCK);
+    const loaded = doc.getBlock('blk-1');
+    expect(loaded!.attrDefs).toHaveLength(2);
+    expect(loaded!.attrDefs![1].tag).toBe('AUTOR');
+  });
+});
+
+// ─── Rendering: elementToPrimitives mit attrDefs ────────────
+
+describe('D12: RenderAdapter zeichnet Attr-Texte', () => {
+  it('Instanz mit attrValues erzeugt text-Primitives pro Attribut', () => {
+    const el = instance({ PROJEKT: 'Halle A', AUTOR: 'L. Admin' });
+    const prims = elementToPrimitives(el, BLOCK.attrDefs);
+    const texts = prims.filter((p) => p.kind === 'text');
+    expect(texts).toHaveLength(2);
+    const proj = texts.find((t) => (t as { text: string }).text.includes('PROJEKT'));
+    expect(proj).toBeDefined();
+    expect((proj as { text: string }).text).toContain('Halle A');
+    const autor = texts.find((t) => (t as { text: string }).text.includes('AUTOR'));
+    expect((autor as { text: string }).text).toContain('L. Admin');
+  });
+
+  it('Fehlender Wert faellt auf attrDefs.defaultValue zurueck', () => {
+    const el = instance({});
+    const prims = elementToPrimitives(el, BLOCK.attrDefs);
+    const texts = prims.filter((p) => p.kind === 'text');
+    const proj = texts.find((t) => (t as { text: string }).text.includes('PROJEKT'));
+    expect((proj as { text: string }).text).toContain('Unbenannt');
+  });
+
+  it('Ohne attrDefs-Parameter: kein Attr-Text-Rendering (abwaertskompatibel)', () => {
+    const el = instance({ PROJEKT: 'Halle A' });
+    const prims = elementToPrimitives(el);
+    expect(prims.filter((p) => p.kind === 'text')).toHaveLength(0);
+  });
+
+  it('Instanz ohne attrValues mit attrDefs: defaults werden gezeichnet', () => {
+    const el: CADElement = {
+      id: 'inst-2', type: 'block_instance', layerId: 'layer-0',
+      x: 0, y: 0, width: 0, height: 0,
+      properties: { blockId: 'blk-1', scale: 1 },
+    } as unknown as CADElement;
+    const prims = elementToPrimitives(el, BLOCK.attrDefs);
+    const texts = prims.filter((p) => p.kind === 'text');
+    expect(texts).toHaveLength(2);
+  });
+
+  it('Text-Positionen gestaffelt unterhalb der Instanz-Position', () => {
+    const el = instance({ PROJEKT: 'A', AUTOR: 'B' });
+    const prims = elementToPrimitives(el, BLOCK.attrDefs);
+    const texts = prims.filter((p) => p.kind === 'text') as Array<{ kind: 'text'; at: { x: number; y: number }; text: string }>;
+    expect(texts[0].at.x).toBe(100);
+    expect(texts[0].at.y).toBeCloseTo(100 - 8, 0);
+    expect(texts[1].at.y).toBeLessThan(texts[0].at.y);
+  });
+});

frontend/tests/blockThumbnail.test.ts

@@ -0,0 +1,45 @@
+/**
+ * BlockThumbnail Tests (Task F3) – SVG-Thumbnail aus elementToPrimitives
+ */
+import { describe, it, expect } from 'vitest';
+import { generateBlockSvg, primitivesToSvg } from '../src/utils/blockThumbnail';
+import { elementToPrimitives } from '../src/render/pixi/elementDrawers';
+import type { CADElement } from '../src/types/cad.types';
+
+describe('blockThumbnail (F3)', () => {
+  const chair: CADElement = {
+    id: 'c1',
+    type: 'chair',
+    layerId: 'l0',
+    x: 100,
+    y: 200,
+    width: 40,
+    height: 40,
+    properties: {},
+  } as CADElement;
+
+  it('erzeugt SVG mit viewBox aus Element-BBox', () => {
+    const svg = generateBlockSvg([chair]);
+    expect(svg).toContain('<svg');
+    expect(svg).toContain('viewBox');
+  });
+
+  it('konvertiert rect-Primitive in SVG-rect', () => {
+    const prims = elementToPrimitives(chair);
+    expect(prims.length).toBeGreaterThan(0);
+    const svg = primitivesToSvg(prims);
+    expect(svg).toContain('<rect');
+  });
+
+  it('liefert leeren String für leere Auswahl', () => {
+    expect(generateBlockSvg([])).toBe('');
+  });
+
+  it('BBox umfasst mehrere Elemente korrekt', () => {
+    const a: CADElement = { ...chair, id: 'a', x: 0, y: 0 };
+    const b: CADElement = { ...chair, id: 'b', x: 500, y: 300 };
+    const svg = generateBlockSvg([a, b]);
+    // chair-Drawer erzeugt rect-Zentrum bei (el.x - w/2) → BBox -40..500/-40..300 + PAD 10
+    expect(svg).toContain('viewBox="-50 -50 560 360"');
+  });
+});

frontend/tests/bugs.regress.test.ts

@@ -0,0 +1,173 @@
+/**
+ * Regressions-Tests für bekannte Bugs BUG-1, BUG-1b, BUG-2.
+ * Diese Tests sind VOR dem jeweiligen Fix ROT (dokumentiertes Fehlverhalten)
+ * und müssen danach GRÜN sein.
+ */
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import { SeatingService } from '../src/services/seatingService';
+import { trimElement, offsetElement } from '../src/tools/modification/geometry';
+import type { CADElement } from '../src/types/cad.types';
+import { RenderEngine } from '../src/canvas/RenderEngine';
+import { ZoomPanController } from '../src/canvas/ZoomPanController';
+import { SpatialIndex } from '../src/canvas/SpatialIndex';
+import { LayerManager } from '../src/canvas/LayerManager';
+
+// ── Helfer (Muster aus tests/geometry.test.ts) ─────────────
+function makeLine(id: string, x1: number, y1: number, x2: number, y2: number): CADElement {
+  return {
+    id,
+    type: 'line',
+    layerId: 'layer-1',
+    x: (x1 + x2) / 2,
+    y: (y1 + y2) / 2,
+    width: Math.abs(x2 - x1),
+    height: Math.abs(y2 - y1),
+    properties: { x1, y1, x2, y2 },
+  } as unknown as CADElement;
+}
+
+function makeCircle(id: string, cx: number, cy: number, r: number): CADElement {
+  return {
+    id,
+    type: 'circle',
+    layerId: 'layer-1',
+    x: cx,
+    y: cy,
+    width: r * 2,
+    height: r * 2,
+    properties: { radius: r },
+  } as unknown as CADElement;
+}
+
+// ── BUG-1: rowId-Kollision bei schnellem Erzeugen ───────────
+describe('BUG-1: seating row ids', () => {
+  it('zwei direkt hintereinander erzeugte Reihen haben unterschiedliche rowIds', () => {
+    const svc = new SeatingService();
+    const a = svc.createSeatingRow(0, 0, 'layer-1');
+    const b = svc.createSeatingRow(0, 100, 'layer-1');
+    const ids = new Set([a[0].properties.rowId, b[0].properties.rowId]);
+    expect(ids.size).toBe(2);
+  });
+});
+
+// ── BUG-1b: Block-Reihen ohne eigene rowId ──────────────────
+describe('BUG-1b: seating block row ids', () => {
+  it('jede Reihe eines Blocks hat eine eigene, definierte rowId', () => {
+    const svc = new SeatingService();
+    const els = svc.createSeatingBlock(0, 0, 'layer-1', { rows: 3, cols: 2 });
+    expect(els.length).toBe(6);
+    const rowIds = new Set(els.map((e) => e.properties.rowId));
+    expect(rowIds.size).toBe(3);
+    for (const rid of rowIds) expect(rid).toBeDefined();
+  });
+});
+
+// ── BUG-2: Trim an Kreis scheitert (findIntersection nur Gerade×Gerade) ──
+describe('BUG-2: trim line at circle', () => {
+  it('trimElement(Linie, Kreis) liefert ein Ergebnis statt null', () => {
+    // Linie von (0,0) nach (200,0) schneidet Kreis (Zentrum 100,0, Radius 40)
+    // an x=60 und x=140 → Schnitt existiert eindeutig.
+    const line = makeLine('l1', 0, 0, 200, 0);
+    const circle = makeCircle('c1', 100, 0, 40);
+    const result = trimElement(line, circle);
+    expect(result).not.toBeNull();
+  });
+});
+
+// ── BUG-3: Offset ignorierte die Klickseite ─────────────────
+describe('BUG-3: offset respects click side', () => {
+  it('side=-1 versetzt Linie entgegen der Normalenrichtung', () => {
+    // Linie (100,100)→(300,100): Laufrichtung +x.
+    // Normale (-dy,dx)=(0,1) zeigt in Canvas-Koordinaten nach UNTEN (+y).
+    const line = makeLine('l1', 100, 100, 300, 100);
+    const result = offsetElement(line, 20, -1);
+    expect(result.properties.y1).toBeCloseTo(80); // nach OBEN versetzt
+    expect(result.properties.y2).toBeCloseTo(80);
+  });
+
+  it('side=+1 versetzt Linie in Normalenrichtung (Default wie vorher)', () => {
+    const line = makeLine('l1', 100, 100, 300, 100);
+    const result = offsetElement(line, 20, 1);
+    expect(result.properties.y1).toBeCloseTo(120); // nach UNTEN versetzt
+    expect(result.properties.y2).toBeCloseTo(120);
+  });
+
+  it('ohne side bleibt Verhalten identisch zur alten API (Rueckwaertskompatibilitaet)', () => {
+    const line = makeLine('l1', 100, 100, 300, 100);
+    const result = offsetElement(line, 20);
+    expect(result.properties.y1).toBeCloseTo(120);
+  });
+
+  it('Kreis: side=-1 verkleinert Radius, side=+1 vergroessert', () => {
+    const circle = makeCircle('c1', 0, 0, 50);
+    expect(offsetElement(circle, 10, -1).properties.radius).toBeCloseTo(40);
+    expect(offsetElement(circle, 10, 1).properties.radius).toBeCloseTo(60);
+  });
+});
+
+// ── BUG-4: Hintergrundbild wurde pro Frame neu geladen ──────
+describe('BUG-4: background image cached', () => {
+  let imageCount: number;
+  let OriginalImage: typeof Image;
+
+  beforeEach(() => {
+    imageCount = 0;
+    OriginalImage = global.Image;
+    // Bild-Stub: zaehlt Konstruktur-Aufrufe; simuliert Browser-Cache-Bild
+    // (complete=true sofort verfuegbar, onload als Mikrotask wie async decode)
+    class FakeImage {
+      complete = true;
+      naturalWidth = 800;
+      width = 800;
+      height = 600;
+      onload: (() => void) | null = null;
+      private internalSrc = '';
+      get src(): string {
+        return this.internalSrc;
+      }
+      set src(value: string) {
+        this.internalSrc = value;
+        queueMicrotask(() => this.onload?.());
+      }
+      constructor() {
+        imageCount += 1;
+      }
+    }
+    (global as { Image: unknown }).Image = FakeImage as unknown as typeof Image;
+  });
+
+  afterEach(() => {
+    (global as { Image: unknown }).Image = OriginalImage;
+  });
+
+  function createEngine(): RenderEngine {
+    const canvas = document.createElement('canvas');
+    canvas.width = 800;
+    canvas.height = 600;
+    const zoomPan = new ZoomPanController(canvas);
+    const spatialIndex = new SpatialIndex();
+    const layerManager = new LayerManager();
+    return new RenderEngine(canvas, zoomPan, spatialIndex, layerManager);
+  }
+
+  it('lädt das Bild pro Quellwechsel nur EINMAL, weitere Frames nutzen den Cache', async () => {
+    const engine = createEngine();
+    const DATA_URL = 'data:image/png;base64,iVBORw0KGgo=';
+    engine.setOptions({ backgroundSrc: DATA_URL, backgroundOpacity: 0.5 });
+
+    // Frame 1: legt genau ein Image an und cachet es (complete=true)
+    engine.render();
+    expect(imageCount).toBe(1);
+
+    // Weitere Frames mit identischer src: dürfen KEIN neues Image erzeugen
+    engine.render();
+    engine.render();
+    engine.render();
+    expect(imageCount).toBe(1);
+
+    // Ausstehende Mikrotasks (simuliertes onload) abwarten, dann erneut prüfen:
+    await Promise.resolve();
+    engine.render();
+    expect(imageCount).toBe(1); // vorher (Bug): jedes render() erzeugte ein neues Image
+  });
+});

frontend/tests/cadDocument.test.ts

@@ -0,0 +1,121 @@
+/**
+ * CADDocument Tests (Task A2b).
+ * Kern-Verhalten: CRUD, Shallow-Merge, Transaktion = 1 Undo-Schritt,
+ * undo/redo-Stacks, deleteElements selektiv.
+ */
+import { describe, it, expect } from 'vitest';
+import { CADDocument } from '../src/kernel/document/CADDocument';
+import { createInMemoryDoc } from './helpers/inMemoryDoc';
+import type { CADElement } from '../src/types/cad.types';
+
+function makeEl(id: string, props: Record<string, unknown> = {}): CADElement {
+  return {
+    id,
+    type: 'rect',
+    layerId: 'layer-1',
+    x: 10,
+    y: 20,
+    width: 30,
+    height: 40,
+    properties: props,
+  } as unknown as CADElement;
+}
+
+function makeDoc(): { doc: CADDocument } {
+  const { ydoc } = createInMemoryDoc();
+  return { doc: new CADDocument(ydoc) };
+}
+
+describe('CADDocument', () => {
+  it('a) addElement → getAllElements enthaelt es', () => {
+    const { doc } = makeDoc();
+    doc.addElement(makeEl('e1'));
+    const all = doc.getAllElements();
+    expect(all.length).toBe(1);
+    expect(all[0].id).toBe('e1');
+    expect(doc.getElement('e1')).toBeDefined();
+    expect(doc.getElement('missing')).toBeUndefined();
+  });
+
+  it('b) transact um zwei addElements = EIN Undo-Schritt entfernt BEIDE', () => {
+    const { doc } = makeDoc();
+    doc.transact(() => {
+      doc.addElement(makeEl('a'));
+      doc.addElement(makeEl('b'));
+    });
+    expect(doc.getAllElements().length).toBe(2);
+    expect(doc.canUndo()).toBe(true);
+
+    expect(doc.undo()).toBe(true);
+    expect(doc.getAllElements().length).toBe(0); // beide weg mit einem undo!
+    expect(doc.canUndo()).toBe(false);
+  });
+
+  it('c) redo stellt beide Elemente wieder her', () => {
+    const { doc } = makeDoc();
+    doc.transact(() => {
+      doc.addElement(makeEl('a'));
+      doc.addElement(makeEl('b'));
+    });
+    doc.undo();
+    expect(doc.getAllElements().length).toBe(0);
+
+    expect(doc.canRedo()).toBe(true);
+    expect(doc.redo()).toBe(true);
+    expect(doc.getAllElements().length).toBe(2);
+    expect(doc.getElement('a')).toBeDefined();
+    expect(doc.getElement('b')).toBeDefined();
+  });
+
+  it('d) updateElement merged properties SHALLOW (bestehende Keys bleiben)', () => {
+    const { doc } = makeDoc();
+    doc.addElement(makeEl('m', { fill: 'red', rotation: 45, stroke: 'black' }));
+
+    doc.updateElement('m', { properties: { fill: 'blue' } });
+    const el = doc.getElement('m')!;
+    expect(el.properties.fill).toBe('blue');       // ueberschrieben
+    expect(el.properties.rotation).toBe(45);        // erhalten
+    expect(el.properties.stroke).toBe('black');     // erhalten
+  });
+
+  it('d2) updateElement kann Top-Level-Felder setzen und wirft bei fehlender ID', () => {
+    const { doc } = makeDoc();
+    doc.addElement(makeEl('m'));
+    doc.updateElement('m', { x: 999 });
+    expect(doc.getElement('m')!.x).toBe(999);
+    expect(() => doc.updateElement('ghost', { x: 1 })).toThrow(/nicht gefunden/);
+  });
+
+  it('e) deleteElements entfernt nur die genannten IDs', () => {
+    const { doc } = makeDoc();
+    doc.transact(() => {
+      doc.addElement(makeEl('keep1'));
+      doc.addElement(makeEl('del1'));
+      doc.addElement(makeEl('del2'));
+      doc.addElement(makeEl('keep2'));
+    });
+
+    doc.deleteElements(['del1', 'del2', 'unbekannt']); // unbekannte still ignorieren
+    const ids = doc.getAllElements().map((e) => e.id).sort();
+    expect(ids).toEqual(['keep1', 'keep2']);
+  });
+
+  it('undo nach deleteElements stellt geloeschte Elemente wieder her', () => {
+    const { doc } = makeDoc();
+    doc.addElement(makeEl('x1'));
+    doc.addElement(makeEl('x2'));
+
+    doc.deleteElements(['x1']);
+    expect(doc.getAllElements().length).toBe(1);
+
+    doc.undo(); // Delete rueckgaengig
+    expect(doc.getAllElements().length).toBe(2);
+    expect(doc.getElement('x1')).toBeDefined();
+  });
+
+  it('undo/redo liefern false auf leeren Stacks', () => {
+    const { doc } = makeDoc();
+    expect(doc.undo()).toBe(false);
+    expect(doc.redo()).toBe(false);
+  });
+});

frontend/tests/constructionTools.test.ts

@@ -0,0 +1,147 @@
+/**
+ * Task D3 – Point/XLine/Ray: Konstruktions-Elemente.
+ *
+ * pointTool: Klick-Platzierer (kleiner Kreis mit point:true-Marker,
+ * r=1.5 wie DXF-POINT-Import). xlineTool: 2 Klicks (Basis+Richtung),
+ * sehr lange Linie in BEIDE Richtungen. rayTool: halblang (nur eine
+ * Richtung). Alle mit construction:true und auf defpoints-Layer
+ * (auto-angelegt falls fehlt).
+ */
+import { describe, it, expect, beforeEach } from 'vitest';
+import { pointTool, xlineTool, rayTool } from '../src/plugins/builtin/core-drawing';
+import { CADDocument } from '../src/kernel/document/CADDocument';
+import { createInMemoryDoc } from './helpers/inMemoryDoc';
+import type { CADElement, Pt } from '../src/types/cad.types';
+
+function mkCtx() {
+  const { ydoc } = createInMemoryDoc();
+  const doc = new CADDocument(ydoc);
+  const previews: (CADElement | null)[] = [];
+  const statuses: string[] = [];
+  const ctx: any = {
+    doc,
+    options: {},
+    setStatus: (m: string) => statuses.push(m),
+    setPreview: (el: CADElement | null) => previews.push(el),
+  };
+  return { ctx, doc, previews, statuses };
+}
+
+function pe(x: number, y: number): { world: Pt } {
+  return { world: { x, y } } as never;
+}
+
+beforeEach(() => {
+  pointTool.handlers.cancel?.({ setStatus: () => {}, setPreview: () => {} } as never);
+  xlineTool.handlers.cancel?.({ setStatus: () => {}, setPreview: () => {} } as never);
+  rayTool.handlers.cancel?.({ setStatus: () => {}, setPreview: () => {} } as never);
+});
+
+describe('D3: pointTool', () => {
+  it('Klick platziert Kreis mit point-Marker (r=1.5, wie DXF POINT)', () => {
+    const { ctx, doc } = mkCtx();
+    pointTool.handlers.down!(pe(55, 66), ctx);
+    const els = doc.getAllElements();
+    expect(els).toHaveLength(1);
+    const el = els[0];
+    expect(el.type).toBe('circle');
+    expect(el.x).toBe(55);
+    expect(el.y).toBe(66);
+    expect(el.properties.radius).toBe(1.5);
+    expect(el.properties.point).toBe(true);
+  });
+
+  it('defpoints-Layer wird automatisch angelegt falls fehlt', () => {
+    const { ctx, doc } = mkCtx();
+    expect(doc.getLayer('defpoints')).toBeUndefined();
+    pointTool.handlers.down!(pe(0, 0), ctx);
+    expect(doc.getLayer('defpoints')).toBeDefined();
+    expect(doc.getLayer('defpoints')!.name).toBe('defpoints');
+  });
+
+  it('Element landet auf defpoints-Layer mit construction:true', () => {
+    const { ctx, doc } = mkCtx();
+    pointTool.handlers.down!(pe(10, 10), ctx);
+    const el = doc.getAllElements()[0];
+    expect(el.layerId).toBe('defpoints');
+    expect(el.properties.construction).toBe(true);
+  });
+});
+
+describe('D3: xlineTool (Konstruktionslinie, beide Richtungen)', () => {
+  it('2 Klicks erzeugen sehr lange Linie durch beide Punkte in BEIDE Richtungen', () => {
+    const { ctx, doc } = mkCtx();
+    xlineTool.handlers.down!(pe(0, 0), ctx);
+    xlineTool.handlers.down!(pe(10, 10), ctx);
+    const els = doc.getAllElements();
+    expect(els).toHaveLength(1);
+    const el = els[0];
+    expect(el.type).toBe('line');
+    const dx = (el.properties.x2 as number) - (el.properties.x1 as number);
+    const dy = (el.properties.y2 as number) - (el.properties.y1 as number);
+    // Sehr lange: Länge >> Distanz der beiden Klicks (14.14)
+    expect(Math.hypot(dx, dy)).toBeGreaterThan(100000);
+    // Mittelpunkt der Linie = Basispunkt
+    expect((el.properties.x1 as number) + dx / 2).toBeCloseTo(0, 3);
+    expect((el.properties.y1 as number) + dy / 2).toBeCloseTo(0, 3);
+  });
+
+  it('Element auf defpoints-Layer mit construction:true', () => {
+    const { ctx, doc } = mkCtx();
+    xlineTool.handlers.down!(pe(0, 0), ctx);
+    xlineTool.handlers.down!(pe(5, 0), ctx);
+    const el = doc.getAllElements()[0];
+    expect(el.layerId).toBe('defpoints');
+    expect(el.properties.construction).toBe(true);
+  });
+
+  it('Preview bei move nach erstem Klick', () => {
+    const { ctx, previews } = mkCtx();
+    xlineTool.handlers.down!(pe(0, 0), ctx);
+    xlineTool.handlers.move!(pe(50, 50), ctx);
+    expect(previews.length).toBeGreaterThanOrEqual(1);
+  });
+
+  it('Erster Klick ohne zweiten erzeugt NICHTS (Session-State)', () => {
+    const { ctx, doc } = mkCtx();
+    xlineTool.handlers.down!(pe(0, 0), ctx);
+    expect(doc.getAllElements()).toHaveLength(0);
+  });
+});
+
+describe('D3: rayTool (Strahl, nur EINE Richtung)', () => {
+  it('2 Klicks erzeugen Linie ab Basispunkt NUR in Zugrichtung', () => {
+    const { ctx, doc } = mkCtx();
+    rayTool.handlers.down!(pe(0, 0), ctx);
+    rayTool.handlers.down!(pe(10, 0), ctx);
+    const el = doc.getAllElements()[0];
+    expect(el.type).toBe('line');
+    expect(el.properties.x1).toBe(0);
+    expect(el.properties.y1).toBe(0);
+    // Endpunkt weit in +x-Richtung
+    expect((el.properties.x2 as number)).toBeGreaterThanOrEqual(100000);
+    // NICHT in Gegenrichtung: x1 ist exakt der Basispunkt
+    expect(el.properties.x1).toBe(0);
+  });
+
+  it('construction:true + defpoints-Layer', () => {
+    const { ctx, doc } = mkCtx();
+    rayTool.handlers.down!(pe(0, 0), ctx);
+    rayTool.handlers.down!(pe(0, 10), ctx);
+    const el = doc.getAllElements()[0];
+    expect(el.layerId).toBe('defpoints');
+    expect(el.properties.construction).toBe(true);
+  });
+});
+
+describe('D3: Manifeste', () => {
+  it('ids/ribbonTab/tags korrekt', () => {
+    expect(pointTool.manifest.id).toBe('point');
+    expect(xlineTool.manifest.id).toBe('xline');
+    expect(rayTool.manifest.id).toBe('ray');
+    for (const t of [pointTool, xlineTool, rayTool]) {
+      expect(t.manifest.ribbonTab).toBe('canvas');
+      expect((t.manifest.tags ?? [])).toContain('basic');
+    }
+  });
+});

frontend/tests/dispatcher.test.ts

@@ -0,0 +1,138 @@
+/**
+ * InteractionDispatcher Tests (Task A2).
+ * Prüft Event-Routing gegen ein Fake-Werkzeug ohne echte Registry:
+ * Reihenfolge down→move→up, ESC/Rechtsklick cancel, move nur bei aktiver Session,
+ * unbekanntes Tool → kein Routing.
+ */
+import { describe, it, expect, vi, afterEach } from 'vitest';
+import { InteractionDispatcher } from '../src/interaction/dispatcher';
+import type { ToolExtensionV2 } from '../src/plugins/types';
+import type { ZoomPanController } from '../src/canvas/ZoomPanController';
+
+function makeFakeZoomPan(): ZoomPanController {
+  return {
+    screenToWorld: (sx: number, sy: number) => ({ x: sx * 2, y: sy * 3 }),
+  } as unknown as ZoomPanController;
+}
+
+function makeRecordingTool(id = 'fake'): { tool: ToolExtensionV2; log: string[] } {
+  const log: string[] = [];
+  const tool: ToolExtensionV2 = {
+    manifest: { id, label: 'Fake', icon: 'f', ribbonTab: 'tools' },
+    optionsSchema: [],
+    handlers: {
+      down: () => log.push('down'),
+      move: () => log.push('move'),
+      up: () => log.push('up'),
+      key: () => false,
+      cancel: () => log.push('cancel'),
+    },
+  };
+  return { tool, log };
+}
+
+function fire(canvas: HTMLCanvasElement, type: string, opts: Partial<PointerEventInit> = {}): PointerEvent {
+  const e = new PointerEvent(type, {
+    bubbles: true,
+    clientX: 100,
+    clientY: 50,
+    button: 0,
+    ...opts,
+  });
+  if (type === 'pointerdown') canvas.dispatchEvent(e);
+  else window.dispatchEvent(e);
+  return e;
+}
+
+function fireKey(key: string): KeyboardEvent {
+  const e = new KeyboardEvent('keydown', { key, bubbles: true });
+  window.dispatchEvent(e);
+  return e;
+}
+
+describe('InteractionDispatcher', () => {
+  let canvas: HTMLCanvasElement;
+
+  afterEach(() => {
+    canvas?.remove();
+  });
+
+  function setup(tool?: ToolExtensionV2) {
+    canvas = document.createElement('canvas');
+    document.body.appendChild(canvas);
+    const dispatcher = new InteractionDispatcher(canvas, {
+      zoomPan: makeFakeZoomPan(),
+      toolLookup: tool ? () => tool : undefined,
+    });
+    return { dispatcher };
+  }
+
+  it('routet down→move→up in Reihenfolge an das aktive Tool', () => {
+    const { tool, log } = makeRecordingTool();
+    const { dispatcher } = setup(tool);
+    dispatcher.setActive('fake');
+
+    fire(canvas, 'pointerdown');
+    fire(window, 'pointermove');
+    fire(window, 'pointerup');
+
+    expect(log).toEqual(['down', 'move', 'up']);
+    expect(dispatcher.getActive()?.manifest.id).toBe('fake');
+  });
+
+  it('ignoriert move/up ohne vorheriges down (Session-Guard)', () => {
+    const { tool, log } = makeRecordingTool();
+    const { dispatcher } = setup(tool);
+    dispatcher.setActive('fake');
+
+    fire(window, 'pointermove'); // keine Session aktiv
+    fire(window, 'pointerup');
+    expect(log).toEqual([]);
+  });
+
+  it('ESC ruft cancel und beendet die Session', () => {
+    const { tool, log } = makeRecordingTool();
+    const { dispatcher } = setup(tool);
+    dispatcher.setActive('fake');
+
+    fire(canvas, 'pointerdown');
+    fireKey('Escape');
+    expect(log).toEqual(['down', 'cancel']);
+
+    fire(window, 'pointermove'); // Session beendet → kein move mehr
+    expect(log).toEqual(['down', 'cancel']);
+  });
+
+  it('Rechtsklick bricht ab, ohne down durchzureichen', () => {
+    const { tool, log } = makeRecordingTool();
+    const { dispatcher } = setup(tool);
+    dispatcher.setActive('fake');
+
+    fire(canvas, 'pointerdown', { button: 2 });
+    expect(log).toEqual(['cancel']);
+  });
+
+  it('setActive(null) deaktiviert Routing komplett', () => {
+    const { tool, log } = makeRecordingTool();
+    const { dispatcher } = setup(tool);
+    dispatcher.setActive('fake');
+    dispatcher.setActive(null);
+    fire(canvas, 'pointerdown');
+    fire(window, 'pointermove');
+    expect(log).toEqual([]);
+  });
+
+  it('liefert Weltkoordinaten aus zoomPan.screenToWorld', () => {
+    let received: { x: number; y: number } | null = null;
+    const tool: ToolExtensionV2 = {
+      manifest: { id: 'geo', label: 'G', icon: 'g', ribbonTab: 't' },
+      optionsSchema: [],
+      handlers: { down: (e) => (received = { ...e.world }) },
+    };
+    const { dispatcher } = setup(tool);
+    dispatcher.setActive('geo');
+    fire(canvas, 'pointerdown', { clientX: 100, clientY: 50 });
+    // fake screenToWorld: x*2, y*3 → (200, 150)
+    expect(received).toEqual({ x: 200, y: 150 });
+  });
+});

frontend/tests/documentService.test.ts

@@ -0,0 +1,56 @@
+/**
+ * documentService Tests (Task A4.11).
+ * Prüft Registrierung/Löschung des aktiven Dokuments und die
+ * Undo/Redo-Delegation an CADDocument.
+ */
+import { describe, it, expect, afterEach } from 'vitest';
+import { setActiveDocument, getActiveDocument, undoActive, redoActive } from '../src/kernel/document/documentService';
+import { CADDocument } from '../src/kernel/document/CADDocument';
+import { createInMemoryDoc } from './helpers/inMemoryDoc';
+import type { CADElement } from '../src/types/cad.types';
+
+function makeEl(id: string): CADElement {
+  return {
+    id,
+    type: 'rect',
+    layerId: 'l',
+    x: 0,
+    y: 0,
+    width: 1,
+    height: 1,
+    properties: {},
+  } as unknown as CADElement;
+}
+
+afterEach(() => {
+  setActiveDocument(null);
+});
+
+describe('documentService', () => {
+  it('registriert und entregistriert das aktive Dokument', () => {
+    const { ydoc } = createInMemoryDoc();
+    const doc = new CADDocument(ydoc);
+    setActiveDocument(doc);
+    expect(getActiveDocument()).toBe(doc);
+    setActiveDocument(null);
+    expect(getActiveDocument()).toBeNull();
+  });
+
+  it('undoActive delegiert an das registrierte Dokument', () => {
+    const { ydoc } = createInMemoryDoc();
+    const doc = new CADDocument(ydoc);
+    doc.addElement(makeEl('x1'));
+    setActiveDocument(doc);
+
+    expect(undoActive()).toBe(true);      // Element wird entfernt
+    expect(doc.getAllElements().length).toBe(0);
+    expect(redoActive()).toBe(true);       // wiederhergestellt
+    expect(doc.getAllElements().length).toBe(1);
+  });
+
+  it('undoActive liefert false ohne aktives Dokument', () => {
+    setActiveDocument(null);
+    expect(undoActive()).toBe(false);
+    expect(redoActive()).toBe(false);
+  });
+});

frontend/tests/dxfParserF5.test.ts

@@ -0,0 +1,230 @@
+/**
+ * Task F5 – DXF-Parser-Erweiterungstests.
+ *
+ * Neue Entity-Abdeckung: ELLIPSE (als Polyline-Approx), SPLINE (grad<=3 →
+ * Polyline via de-Boor), MTEXT (Formatcodes gecleanup), POINT, ATTDEF,
+ * INSERT mit MINSERT-Arrays und HATCH (forward-kompatibel_via Fake-Entity).
+ * Plus strukturierter Fehlerreport (skippedEntities) neben warnings.
+ */
+import { describe, it, expect } from 'vitest';
+import { parseDXF, entityToCADElement, expandInsert } from '../src/services/dxfParser';
+import type { CADLayer } from '../src/types/cad.types';
+
+const layer0: CADLayer = {
+  id: 'dxf-layer-0', name: '0', visible: true, locked: false,
+  color: '#ffffff', lineType: 'solid', transparency: 0, sortOrder: 0, parentId: null,
+};
+const layers = new Map([['0', layer0]]);
+
+function dxfOf(entityBody: string): string {
+  return `0\nSECTION\n2\nENTITIES\n${entityBody}0\nENDSEC\n0\nEOF\n`;
+}
+
+function ptsOf(el: { properties: { points?: Array<{ x: number; y: number }> } }): Array<{ x: number; y: number }> {
+  return el.properties.points ?? [];
+}
+
+describe('F5: ELLIPSE', () => {
+  it('volle Ellipse → geschlossene Polyline mit 64 Punkten und korrekter BBox', () => {
+    const el = entityToCADElement({
+      type: 'ELLIPSE', layer: '0',
+      center: { x: 0, y: 0 },
+      majorAxisEndPoint: { x: 100, y: 0 },
+      axisRatio: 0.5,
+      startAngle: 0, endAngle: Math.PI * 2,
+    } as any, layers);
+    expect(el).not.toBeNull();
+    expect(el!.type).toBe('polyline');
+    const pts = ptsOf(el!);
+    expect(pts.length).toBe(64);
+    const xs = pts.map((p) => p.x), ys = pts.map((p) => p.y);
+    expect(Math.max(...xs)).toBeCloseTo(100, 0);
+    expect(Math.min(...xs)).toBeCloseTo(-100, 0);
+    expect(Math.max(...ys)).toBeCloseTo(50, 0);
+    expect(Math.min(...ys)).toBeCloseTo(-50, 0);
+  });
+
+  it('rotierte Ellipse respektiert majorAxisEndPoint-Winkel', () => {
+    const el = entityToCADElement({
+      type: 'ELLIPSE', layer: '0',
+      center: { x: 0, y: 0 },
+      majorAxisEndPoint: { x: 0, y: 100 }, // 90° rotiert
+      axisRatio: 0.5,
+      startAngle: 0, endAngle: Math.PI * 2,
+    } as any, layers);
+    const pts = ptsOf(el!);
+    expect(Math.max(...pts.map((p) => p.y))).toBeCloseTo(100, 0);
+    expect(Math.max(...pts.map((p) => p.x))).toBeCloseTo(50, 0);
+  });
+
+  it('partielle Ellipse → offene Polyline', () => {
+    const el = entityToCADElement({
+      type: 'ELLIPSE', layer: '0',
+      center: { x: 0, y: 0 },
+      majorAxisEndPoint: { x: 100, y: 0 },
+      axisRatio: 1,
+      startAngle: 0, endAngle: Math.PI,
+    } as any, layers);
+    const pts = ptsOf(el!);
+    expect(pts.length).toBe(32);
+  });
+
+  it('Integration über parseDXF mit echtem ELLIPSE-DXF-String', () => {
+    const res = parseDXF(dxfOf(
+      '0\nELLIPSE\n8\n0\n10\n0\n20\n0\n30\n0\n11\n100\n21\n0\n31\n0\n41\n0.5\n42\n0\n51\n6.283185307179586\n',
+    ));
+    expect(res.skippedEntities).toHaveLength(0);
+    const el = res.elements.find((e) => e.type === 'polyline');
+    expect(el).toBeDefined();
+    expect(ptsOf(el as any).length).toBeGreaterThan(32);
+  });
+});
+
+describe('F5: SPLINE', () => {
+  const controlPoints = [
+    { x: 0, y: 0 }, { x: 33, y: 200 }, { x: 66, y: -100 }, { x: 100, y: 0 },
+  ];
+
+  it('Grad 3 → Polyline-Approx mit mehr Punkten als Kontrollpunkte', () => {
+    const el = entityToCADElement({
+      type: 'SPLINE', layer: '0',
+      degreeOfSplineCurve: 3, controlPoints, fitPoints: [],
+    } as any, layers);
+    expect(el).not.toBeNull();
+    expect(el!.type).toBe('polyline');
+    const pts = ptsOf(el!);
+    expect(pts.length).toBeGreaterThan(16);
+    // Approximation startet/endet bei exakten Kontrollpunkten
+    expect(pts[0].x).toBeCloseTo(0, 3);
+    expect(pts[0].y).toBeCloseTo(0, 3);
+    expect(pts[pts.length - 1].x).toBeCloseTo(100, 3);
+  });
+
+  it('Grad 4 → skipped mit Grund', () => {
+    const el = entityToCADElement({
+      type: 'SPLINE', layer: '0',
+      degreeOfSplineCurve: 4, controlPoints, fitPoints: [],
+    } as any, layers);
+    expect(el).toBeNull();
+  });
+
+  it('ohne Kontrollpunkte → skipped', () => {
+    const el = entityToCADElement({ type: 'SPLINE', layer: '0', degreeOfSplineCurve: 3 } as any, layers);
+    expect(el).toBeNull();
+  });
+});
+
+describe('F5: MTEXT', () => {
+  it('mappt auf text-Element, \\P → Zeilenumbruch, Formatcodes entfernt', () => {
+    const el = entityToCADElement({
+      type: 'MTEXT', layer: '0',
+      position: { x: 10, y: 20 },
+      height: 15, width: 200,
+      text: 'Zeile1\\PZeile2\\A1;\\H2x;Titel',
+    } as any, layers);
+    expect(el).not.toBeNull();
+    expect(el!.type).toBe('text');
+    expect(el!.properties.text).toBe('Zeile1\nZeile2Titel');
+    expect(el!.properties.fontSize).toBe(15);
+  });
+});
+
+describe('F5: POINT', () => {
+  it('mappt auf kleinen gefüllten Kreis mit point-Marker', () => {
+    const el = entityToCADElement({
+      type: 'POINT', layer: '0',
+      position: { x: 55, y: 66 },
+    } as any, layers);
+    expect(el).not.toBeNull();
+    expect(el!.type).toBe('circle');
+    expect(el!.x).toBeCloseTo(55 - 1.5, 5);
+    expect(el!.properties.radius).toBeCloseTo(1.5, 5);
+    expect(el!.properties.point).toBe(true);
+  });
+});
+
+describe('F5: ATTDEF', () => {
+  it('mappt auf text-Element mit tag=Wert und Metadaten', () => {
+    const el = entityToCADElement({
+      type: 'ATTDEF', layer: '0',
+      tag: 'NAME', text: 'Buehne', prompt: 'Name der Buehne',
+      startPoint: { x: 5, y: 5 }, textHeight: 12,
+    } as any, layers);
+    expect(el).not.toBeNull();
+    expect(el!.type).toBe('text');
+    expect(el!.properties.text).toBe('NAME=Buehne');
+    expect(el!.properties.fontSize).toBe(12);
+    expect(el!.properties.tag).toBe('NAME');
+    expect(el!.properties.prompt).toBe('Name der Buehne');
+  });
+
+  it('leerer ATTDEF-Text ohne Tag → skipped', () => {
+    const el = entityToCADElement({ type: 'ATTDEF', layer: '0', startPoint: { x: 0, y: 0 } } as any, layers);
+    expect(el).toBeNull();
+  });
+});
+
+describe('F5: INSERT (MINSERT-Arrays)', () => {
+  it('columnCount/rowCount > 1 erzeugt n-fache Instanzen mit Spacing-Offset', () => {
+    const els = [] as any[];
+    // Der Parser-Einstieg ist parseDXF; INSERT-Expansion passiert dort je Entity — hier via Helper
+    const base = {
+      type: 'INSERT', layer: '0', name: 'stuhl',
+      position: { x: 0, y: 0 }, xScale: 2, yScale: 3, rotation: 0,
+      columnCount: 3, rowCount: 2, columnSpacing: 100, rowSpacing: 50,
+    } as any;
+    const out = expandInsert(base);
+    expect(out).toHaveLength(6);
+    const uniqXs = [...new Set(out.map((e) => e.x))].sort((a, b) => a - b);
+    expect(uniqXs).toEqual([0, 100, 200]);
+    const ys = [...new Set(out.map((e) => e.y))].sort((a, b) => a - b);
+    expect(ys).toEqual([0, 50]);
+    expect(out.every((e) => e.properties.scaleX === 2 && e.properties.scaleY === 3)).toBe(true);
+  });
+
+  it('einfacher INSERT bleibt einzelne Instanz mit kombiniertem scale', () => {
+    const out = expandInsert({
+      type: 'INSERT', layer: '0', name: 'b',
+      position: { x: 5, y: 5 }, xScale: 1, yScale: 1, rotation: 90,
+    } as any);
+    expect(out).toHaveLength(1);
+    expect(out[0].properties.blockId).toBe('b');
+    expect(out[0].properties.rotation).toBe(90);
+  });
+});
+
+describe('F5: HATCH (forward-kompatibel_via Entity-Injektion)', () => {
+  it('HATCH solid → polygon mit hatchPattern', () => {
+    const el = entityToCADElement({
+      type: 'HATCH', layer: '0',
+      patternName: 'SOLID', isSolid: true,
+      boundaryPoints: [{ x: 0, y: 0 }, { x: 100, y: 0 }, { x: 100, y: 100 }, { x: 0, y: 100 }],
+    } as any, layers);
+    expect(el).not.toBeNull();
+    expect(el!.type).toBe('polygon');
+    expect(el!.properties.hatchPattern).toBe('SOLID');
+    expect(ptsOf(el as any)).toHaveLength(4);
+  });
+});
+
+describe('F5: Fehlerreport (skippedEntities)', () => {
+  // Hinweis: dxf-parser 1.1.x verschluckt voellig unbekannte Typen (FOOBAR) schlicht;
+  // valide SPLINE-Entities mit Grad > 3 kommen dagegen durch und werden vom
+  // Mapper mit Grund uebersprungen — genau dafuer ist der Report da.
+  const DEG4_SPLINE = '0\nSPLINE\n8\n0\n71\n4\n11\n0\n21\n0\n11\n10\n21\n0\n11\n20\n21\n0\n11\n30\n21\n0\n';
+
+  it('unbrauchbare Entities (SPLINE Grad 4) landen im Report', () => {
+    const res = parseDXF(dxfOf(DEG4_SPLINE));
+    const types = res.skippedEntities.map((s) => s.type);
+    expect(types).toContain('SPLINE');
+    expect(res.warnings.length).toBeGreaterThan(0);
+    expect(res.skippedEntities[0].reason).toContain('> 3');
+  });
+
+  it('Result enthält skippedEntities-Feld mit type+reason (Design-Vertrag)', () => {
+    const res = parseDXF(dxfOf(DEG4_SPLINE));
+    expect(res.skippedEntities).toHaveLength(1);
+    expect(res.skippedEntities[0].type).toBe('SPLINE');
+    expect(typeof res.skippedEntities[0].reason).toBe('string');
+  });
+});

frontend/tests/dxfWriterF6.test.ts

@@ -0,0 +1,187 @@
+/**
+ * Task F6 – DXF-Writer-Erweiterungstests.
+ *
+ * Deckt ab: BLOCKS+INSERTS mit Name-Mapping/Sanitizing, ATTRIB/SEQEND,
+ * Versionsoption AC1009/AC1015, R12-korrektes POLYLINE statt LWPOLYLINE,
+ * Center-Konvention (circle/arc el.x/el.y = Zentrum) und Grad-Winkel ohne
+ * Doppelkonvertierung — abgesichert über echte write→parse-Roundtrips.
+ */
+import { describe, it, expect } from 'vitest';
+import { writeDXF } from '../src/services/dxfWriter';
+import { parseDXF } from '../src/services/dxfParser';
+import type { CADElement, CADLayer, ProjectData, BlockDefinition } from '../src/types/cad.types';
+
+const layer: CADLayer = {
+  id: 'layer-1', name: 'L1', visible: true, locked: false,
+  color: '#ffffff', lineType: 'solid', transparency: 0, sortOrder: 0, parentId: null,
+};
+
+function mkEl(over: Partial<CADElement> = {}): CADElement {
+  return {
+    id: 'e1', type: 'line', layerId: 'layer-1',
+    x: 0, y: 0, width: 0, height: 0, properties: {},
+    ...over,
+  } as CADElement;
+}
+
+function mkBlock(over: Partial<BlockDefinition> = {}): BlockDefinition {
+  return {
+    id: 'blk-1', name: 'Stuhl Reihe', description: '', category: 'event',
+    elements: [mkEl({ type: 'line', properties: { x1: 0, y1: 0, x2: 100, y2: 0 } })],
+    ...over,
+  };
+}
+
+function mkProj(elements: CADElement[], blocks: BlockDefinition[] = []): ProjectData {
+  return { version: '1', name: 'T', layers: [layer], elements, blocks } as ProjectData;
+}
+
+describe('F6: Version', () => {
+  it('Default ist AC1009 (R12)', () => {
+    expect(writeDXF(mkProj([]))).toContain('AC1009');
+  });
+  it('Option AC1015 setzt Header-Version', () => {
+    expect(writeDXF(mkProj([]), { version: 'AC1015' })).toContain('AC1015');
+  });
+});
+
+describe('F6: BLOCKS + INSERTS', () => {
+  it('BLOCKS-Sektion emittiert sanitisierten Blocknamen, INSERT referenziert gemappten Namen', () => {
+    const out = writeDXF(mkProj([
+      mkEl({ type: 'block_instance', properties: { blockId: 'blk-1' } }),
+    ], [mkBlock()]));
+    expect(out).toContain('BLOCKS');
+    expect(out).toContain('BLOCK');
+    expect(out).toContain('ENDBLK');
+    // Name 'Stuhl Reihe' → 'Stuhl_Reihe' (Leerzeichen sanitizing)
+    expect(out.split('Stuhl_Reihe').length).toBeGreaterThanOrEqual(3); // BLOCK 2/3 + INSERT 2
+    expect(out).toContain('INSERT');
+  });
+
+  it('block_instance ohne Definition bleibt BBox-Fallback (kein INSERT)', () => {
+    const out = writeDXF(mkProj([
+      mkEl({ type: 'block_instance', x: 0, y: 0, width: 100, height: 50, properties: { blockId: 'unknown-block' } }),
+    ]));
+    expect(out).not.toContain('INSERT');
+    expect(out).toContain('POLYLINE');
+  });
+
+  it('Roundtrip: INSERT landet als block_instance mit gemapptem Namen', () => {
+    const out = writeDXF(mkProj([
+      mkEl({ type: 'block_instance', x: 10, y: 20, properties: { blockId: 'blk-1' } }),
+    ], [mkBlock()]));
+    const res = parseDXF(out);
+    const inst = res.elements.find((e) => e.type === 'block_instance');
+    expect(inst).toBeDefined();
+    expect(inst!.properties.blockId).toBe('Stuhl_Reihe');
+    expect(inst!.x).toBe(10);
+    expect(inst!.y).toBe(20);
+  });
+
+  it('ATTDEF aus Blockelement (attdef:true + tag) wird in der BLOCK-Definition emittiert', () => {
+    const blk = mkBlock({
+      elements: [
+        mkEl({ type: 'line', properties: { x1: 0, y1: 0, x2: 50, y2: 0 } }),
+        mkEl({ type: 'text', x: 5, y: 5, properties: { text: 'Buehne', tag: 'NAME', attdef: true, fontSize: 12 } }),
+      ],
+    });
+    const out = writeDXF(mkProj([], [blk]));
+    expect(out).toContain('ATTDEF');
+    expect(out).toContain('NAME');
+  });
+
+  it('Instanz mit attrValues emittiert 66/ATTRIB/SEQEND', () => {
+    const out = writeDXF(mkProj([
+      mkEl({
+        type: 'block_instance', x: 0, y: 0,
+        properties: { blockId: 'blk-1', attrValues: { NAME: 'Halle A' } },
+      }),
+    ], [mkBlock()]));
+    expect(out).toContain('ATTRIB');
+    expect(out).toContain('SEQEND');
+    expect(out).toContain('Halle A');
+    expect(out).toContain('66');
+  });
+});
+
+describe('F6: R12-korrektes POLYLINE', () => {
+  it('polygon → POLYLINE+VERTEX+SEQEND, kein LWPOLYLINE', () => {
+    const out = writeDXF(mkProj([
+      mkEl({
+        type: 'polygon',
+        properties: { points: [{ x: 0, y: 0 }, { x: 100, y: 0 }, { x: 100, y: 100 }] },
+      }),
+    ]));
+    expect(out).toContain('POLYLINE');
+    expect(out).toContain('VERTEX');
+    expect(out).toContain('SEQEND');
+    expect(out).not.toContain('LWPOLYLINE');
+  });
+
+  it('Roundtrip: polygon bleibt geschlossen (shape-Flag 70=1)', () => {
+    const out = writeDXF(mkProj([
+      mkEl({
+        type: 'polygon',
+        properties: { points: [{ x: 0, y: 0 }, { x: 100, y: 0 }, { x: 100, y: 100 }, { x: 0, y: 100 }] },
+      }),
+    ]));
+    const res = parseDXF(out);
+    const poly = res.elements.find((e) => e.type === 'polygon');
+    expect(poly).toBeDefined();
+    expect(res.elements.find((e) => e.type === 'polyline')).toBeUndefined();
+  });
+});
+
+describe('F6: Center- & Winkel-Konvention', () => {
+  it('Writer: circle Zentrum el.x/el.y direkt (kein +width/2)', () => {
+    const out = writeDXF(mkProj([
+      mkEl({ type: 'circle', x: 100, y: 50, width: 60, height: 60, properties: { radius: 30 } }),
+    ]));
+    const res = parseDXF(out);
+    const circ = res.elements.find((e) => e.type === 'circle');
+    expect(circ).toBeDefined();
+    expect(circ!.x).toBeCloseTo(100, 5);
+    expect(circ!.y).toBeCloseTo(50, 5);
+    expect(circ!.properties.radius).toBeCloseTo(30, 5);
+  });
+
+  it('Parser: CIRCLE center landet direkt auf el.x/el.y (Renderer-Konvention)', () => {
+    const dxf = [
+      '0', 'SECTION', '2', 'ENTITIES',
+      '0', 'CIRCLE', '8', '0', '10', '10', '20', '20', '30', '0', '40', '5',
+      '0', 'ENDSEC', '0', 'EOF',
+    ].join(String.fromCharCode(10));
+    const res = parseDXF(dxf);
+    const circ = res.elements.find((e) => e.type === 'circle');
+    expect(circ).toBeDefined();
+    expect(circ!.x).toBe(10);
+    expect(circ!.y).toBe(20);
+    expect(circ!.properties.radius).toBe(5);
+    expect(circ!.width).toBe(10);
+  });
+
+  it('arc/rotation Winkel in Grad ohne Doppelkonvertierung', () => {
+    const out = writeDXF(mkProj([
+      mkEl({ type: 'arc', x: 0, y: 0, width: 20, height: 20, properties: { radius: 10, startAngle: 30, endAngle: 120 } }),
+      mkEl({ type: 'block_instance', x: 0, y: 0, properties: { blockId: 'blk-1', rotation: 45 } }),
+    ], [mkBlock()]));
+    expect(out).toContain('50' + String.fromCharCode(10) + '30');
+    expect(out).toContain('51' + String.fromCharCode(10) + '120');
+    expect(out).toContain('50' + String.fromCharCode(10) + '45');
+    const res = parseDXF(out);
+    const arc = res.elements.find((e) => e.type === 'arc');
+    expect(arc!.properties.startAngle).toBeCloseTo(30, 5);
+  });
+
+  it('rect als geschlossene POLYLINE mit Ecken aus Zentrumskonvention', () => {
+    const out = writeDXF(mkProj([
+      mkEl({ type: 'rect', x: 0, y: 0, width: 100, height: 50, properties: {} }),
+    ]));
+    const res = parseDXF(out);
+    const poly = res.elements[0];
+    const pts = (poly!.properties.points ?? []) as Array<{ x: number; y: number }>;
+    expect(pts.length).toBe(4);
+    expect(pts[0].x).toBeCloseTo(-50, 5);
+    expect(pts[0].y).toBeCloseTo(-25, 5);
+  });
+});

frontend/tests/elementDrawers.test.ts

@@ -0,0 +1,174 @@
+/**
+ * elementToPrimitives Tests (Task C2).
+ * Deckt alle unterstützten Typen + Legacy-Konventionen + Grenzfälle ab.
+ */
+import { describe, it, expect } from 'vitest';
+import { elementToPrimitives } from '../src/render/pixi/elementDrawers';
+import type { CADElement } from '../src/types/cad.types';
+
+function el(id: string, type: string, props: Record<string, unknown> = {}, geom: Partial<CADElement> = {}): CADElement {
+  return {
+    id,
+    type,
+    layerId: 'l',
+    x: 0,
+    y: 0,
+    width: 10,
+    height: 10,
+    properties: props,
+    ...geom,
+  } as unknown as CADElement;
+}
+
+describe('elementToPrimitives', () => {
+  it('line: aus properties.x1..y2 mit stroke/sw', () => {
+    const prims = elementToPrimitives(el('l', 'line', {
+      x1: 0, y1: 0, x2: 100, y2: 50, stroke: '#f00', strokeWidth: 3,
+    }));
+    expect(prims.length).toBe(1);
+    expect(prims[0]).toEqual({
+      kind: 'line', from: { x: 0, y: 0 }, to: { x: 100, y: 50 },
+      stroke: '#f00', strokeWidth: 3,
+    });
+  });
+
+  it('line ohne Koordinaten ergibt leere Liste', () => {
+    expect(elementToPrimitives(el('l', 'line', {}))).toEqual([]);
+  });
+
+  it('rect: x/y ist Zentrum der BBox (Legacy-Konvention)', () => {
+    const prims = elementToPrimitives(el('r', 'rect', { fill: '#123456' }, {
+      x: 100, y: 50, width: 80, height: 40,
+    }));
+    expect(prims.length).toBe(1);
+    const p = prims[0];
+    if (p.kind !== 'rect') throw new Error('erwartete rect');
+    expect(p.x).toBe(60);   // 100 − 40
+    expect(p.y).toBe(30);   // 50 − 20
+    expect(p.w).toBe(80);
+    expect(p.h).toBe(40);
+    expect(p.fill).toBe('#123456');
+  });
+
+  it('rect fill none wird zu null', () => {
+    const prims = elementToPrimitives(el('r', 'rect', { fill: 'none' }));
+    const p = prims[0];
+    if (p.kind !== 'rect') throw new Error('erwartete rect');
+    expect(p.fill).toBeNull();
+  });
+
+  it('circle: radius mit Fallback width/2', () => {
+    const withExplicit = elementToPrimitives(el('c', 'circle', { radius: 25, fill: '#abcdef' }, { x: 5, y: 5 }));
+    const p = withExplicit[0];
+    if (p.kind !== 'circle') throw new Error('erwartete circle');
+    expect(p.radius).toBe(25);
+    expect(p.center).toEqual({ x: 5, y: 5 });
+    expect(p.fill).toBe('#abcdef');
+
+    const byWidth = elementToPrimitives(el('c', 'circle', {}, { width: 120 }));
+    const pb = byWidth[0];
+    if (pb.kind !== 'circle') throw new Error('erwartete circle');
+    expect(pb.radius).toBe(60); // fallback
+  });
+
+  it('arc: Winkel in Grad wie Legacy', () => {
+    const prims = elementToPrimitives(el('a', 'arc', {
+      radius: 40, startAngle: 0, endAngle: 90,
+    }, { x: 0, y: 0 }));
+    const p = prims[0];
+    if (p.kind !== 'arc') throw new Error('erwartete arc');
+    expect(p.startDeg).toBe(0);
+    expect(p.endDeg).toBe(90);
+    expect(p.radius).toBe(40);
+  });
+
+  it('polyline/polygon: points-Array, close je nach Typ', () => {
+    const pts = [{ x: 0, y: 0 }, { x: 10, y: 0 }, { x: 10, y: 10 }];
+    const open = elementToPrimitives(el('pl', 'polyline', { points: pts }));
+    const closed = elementToPrimitives(el('pg', 'polygon', { points: pts }));
+    expect(open.length).toBe(1);
+    expect(closed.length).toBe(1);
+    if (open[0].kind !== 'polyline' || closed[0].kind !== 'polyline') {
+      throw new Error('erwartete polyline');
+    }
+    expect(open[0].close).toBe(false);
+    expect(closed[0].close).toBe(true);
+  });
+
+  it('text: leer nicht gerendert; gefuellt mit fontSize/color', () => {
+    expect(elementToPrimitives(el('t', 'text', { text: '' }))).toEqual([]);
+
+    const filled = elementToPrimitives(el('t', 'text', {
+      text: 'Bühne A', fontSize: 18, color: '#ffffff',
+    }, { x: 50, y: 75 }));
+    expect(filled.length).toBe(1);
+    const p = filled[0];
+    if (p.kind !== 'text') throw new Error('erwartete text');
+    expect(p.text).toBe('Bühne A');
+    expect(p.fontSize).toBe(18);
+    expect(p.color).toBe('#ffffff');
+  });
+
+  it('unbekannter Typ ergibt leere Liste (renderer-sicher)', () => {
+    expect(elementToPrimitives(el('x', 'definitely-unknown'))).toEqual([]);
+  });
+
+  it('dimension: Linie + Label aus value/text', () => {
+    const prims = elementToPrimitives(el('d', 'dimension', {
+      x1: 0, y1: 0, x2: 100, y2: 0, value: '250 cm',
+    }, { x: 50, y: 0 }));
+    expect(prims.length).toBe(2);
+    expect(prims[0].kind).toBe('line');
+    const txt = prims[1];
+    if (txt.kind !== 'text') throw new Error('erwartete text');
+    expect(txt.text).toBe('250 cm');
+  });
+
+  it('leader: Linie + Label am Ende', () => {
+    const prims = elementToPrimitives(el('ld', 'leader', {
+      x1: 10, y1: 10, x2: 80, y2: 60, text: 'A1', fontSize: 14,
+    }));
+    expect(prims.length).toBe(2);
+    expect(prims[0].kind).toBe('line');
+    const txt = prims[1];
+    if (txt.kind !== 'text') throw new Error('erwartete text');
+    expect(txt.text).toBe('A1');
+    expect(txt.fontSize).toBe(14);
+  });
+
+  it('revcloud: geschlossener Punktzug', () => {
+    const prims = elementToPrimitives(el('rc', 'revcloud', {
+      points: [{ x: 0, y: 0 }, { x: 50, y: 0 }, { x: 50, y: 30 }],
+    }));
+    expect(prims.length).toBe(1);
+    const p = prims[0];
+    if (p.kind !== 'polyline') throw new Error('erwartete polyline');
+    expect(p.close).toBe(true);
+  });
+
+  it('chair: gefuelltes Rechteck mit Fallback-Farbe', () => {
+    const prims = elementToPrimitives(el('ch', 'chair', {}, { x: 50, y: 50, width: 20, height: 20 }));
+    const p = prims[0];
+    if (p.kind !== 'rect') throw new Error('erwartete rect');
+    expect(p.fill).toBe('#4a90d9');
+    expect(p.x).toBe(40);
+    expect(p.y).toBe(40);
+  });
+
+  it('table: Kreis mit Fallback-Farbe und Radius aus width', () => {
+    const prims = elementToPrimitives(el('tb', 'table', {}, { x: 0, y: 0, width: 60, height: 60 }));
+    const p = prims[0];
+    if (p.kind !== 'circle') throw new Error('erwartete circle');
+    expect(p.radius).toBe(30);
+    expect(p.fill).toBe('#8b7355');
+  });
+
+  it('stage: dunkles Rechteck', () => {
+    const prims = elementToPrimitives(el('st', 'stage', {}, { x: 0, y: 0, width: 200, height: 100 }));
+    const p = prims[0];
+    if (p.kind !== 'rect') throw new Error('erwartete rect');
+    expect(p.fill).toBe('#3a3a4a');
+    expect(p.w).toBe(200);
+    expect(p.h).toBe(100);
+  });
+});

frontend/tests/ellipseTool.test.ts

@@ -0,0 +1,137 @@
+/**
+ * Task D1 – Ellipse+Bogen-Tool (core-drawing).
+ *
+ * 3-Klick-Interaktion: Klick1=Zentrum, Klick2=RadiusX (Richtung
+ * definiert die Rotation), Klick3=RadiusY. Commit als geschlossene
+ * Polyline (64 Punkte, F5-Parser-Konvention) mit cx/cy/rx/ry/rotation
+ * Metadaten. Ellipsenbogen via startAngle/endAngle-Options → offene
+ * Polyline mit proportionalen Punkten.
+ */
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { ellipseTool } from '../src/plugins/builtin/core-drawing';
+import { CADDocument } from '../src/kernel/document/CADDocument';
+import { createInMemoryDoc } from './helpers/inMemoryDoc';
+import type { CADElement, Pt } from '../src/types/cad.types';
+
+function mkCtx(options: Record<string, unknown> = {}) {
+  const { ydoc } = createInMemoryDoc();
+  const doc = new CADDocument(ydoc);
+  const previews: (CADElement | null)[] = [];
+  const statuses: string[] = [];
+  const ctx: any = {
+    doc,
+    options,
+    setStatus: (m: string) => statuses.push(m),
+    setPreview: (el: CADElement | null) => previews.push(el),
+  };
+  return { ctx, doc, previews, statuses };
+}
+
+function pe(x: number, y: number): { world: Pt } {
+  return { world: { x, y } } as never;
+}
+
+beforeEach(() => {
+  ellipseTool.handlers.cancel?.({ setStatus: () => {}, setPreview: () => {} } as never);
+});
+
+describe('D1: ellipseTool', () => {
+  it('3 Klicks: Zentrum→RadiusX→RadiusY erzeugt geschlossene Ellipse (64 Punkte)', () => {
+    const { ctx, doc } = mkCtx();
+    ellipseTool.handlers.down!(pe(0, 0), ctx);
+    ellipseTool.handlers.down!(pe(100, 0), ctx);   // RadiusX=100, Rotation=0
+    ellipseTool.handlers.down!(pe(0, 50), ctx);     // RadiusY=50
+    const els = doc.getAllElements();
+    expect(els).toHaveLength(1);
+    const el = els[0];
+    expect(el.type).toBe('polygon');
+    const pts = el.properties.points as Pt[];
+    expect(pts.length).toBe(64);
+    // BBox: rx=100, ry=50
+    const xs = pts.map((p) => p.x);
+    const ys = pts.map((p) => p.y);
+    expect(Math.max(...xs)).toBeCloseTo(100, 0);
+    expect(Math.min(...xs)).toBeCloseTo(-100, 0);
+    expect(Math.max(...ys)).toBeCloseTo(50, 0);
+    expect(Math.min(...ys)).toBeCloseTo(-50, 0);
+    // Metadaten
+    expect(el.properties.cx).toBe(0);
+    expect(el.properties.cy).toBe(0);
+    expect(el.properties.rx).toBe(100);
+    expect(el.properties.ry).toBe(50);
+    expect(el.properties.rotation).toBe(0);
+  });
+
+  it('Zugrichtung definiert Rotation: Klick2 nach (0,100) → rotation=90°', () => {
+    const { ctx, doc } = mkCtx();
+    ellipseTool.handlers.down!(pe(0, 0), ctx);
+    ellipseTool.handlers.down!(pe(0, 100), ctx);   // RadiusX zeigt nach unten
+    ellipseTool.handlers.down!(pe(50, 0), ctx);     // RadiusY
+    const el = doc.getAllElements()[0];
+    expect(el.properties.rotation).toBeCloseTo(90, 1);
+    // Rotierte Ellipse: Hauptachse vertikal → maxY ≈ 100
+    const ys = (el.properties.points as Pt[]).map((p) => p.y);
+    expect(Math.max(...ys)).toBeCloseTo(100, 0);
+  });
+
+  it('Preview bei move nach Phase 2 zeigt Ellipse', () => {
+    const { ctx, previews } = mkCtx();
+    ellipseTool.handlers.down!(pe(0, 0), ctx);
+    ellipseTool.handlers.move!(pe(80, 0), ctx);     // RadiusX-Linie
+    ellipseTool.handlers.down!(pe(80, 0), ctx);     // RadiusX fixiert
+    ellipseTool.handlers.move!(pe(0, 40), ctx);    // Ellipsen-Preview mit live ry
+    expect(previews.length).toBeGreaterThanOrEqual(2);
+    const last = previews[previews.length - 1];
+    expect(last).not.toBeNull();
+    expect(last!.type).toBe('polygon');
+  });
+
+  it('Status führt durch die Phasen', () => {
+    const { ctx, statuses } = mkCtx();
+    ellipseTool.handlers.down!(pe(0, 0), ctx);
+    expect(statuses[0]).toContain('Zentrum');
+    ellipseTool.handlers.down!(pe(100, 0), ctx);
+    expect(statuses[1]).toContain('Radius');
+  });
+
+  it('cancel resettet die Messung', () => {
+    const { ctx, doc } = mkCtx();
+    ellipseTool.handlers.down!(pe(0, 0), ctx);
+    ellipseTool.handlers.down!(pe(100, 0), ctx);
+    ellipseTool.handlers.cancel?.(ctx);
+    // Nach cancel startet frisch: nächster Klick = Zentrum (kein Commit)
+    ellipseTool.handlers.down!(pe(0, 0), ctx);
+    expect(doc.getAllElements()).toHaveLength(0);
+  });
+});
+
+describe('D1: Ellipsenbogen (startAngle/endAngle)', () => {
+  it('Options startAngle=0/endAngle=180 erzeugen OFFENE Polyline (32 Punkte)', () => {
+    const { ctx, doc } = mkCtx({ startAngle: 0, endAngle: 180 });
+    ellipseTool.handlers.down!(pe(0, 0), ctx);
+    ellipseTool.handlers.down!(pe(100, 0), ctx);
+    ellipseTool.handlers.down!(pe(0, 50), ctx);
+    const el = doc.getAllElements()[0];
+    expect(el.type).toBe('polyline'); // offen
+    const pts = el.properties.points as Pt[];
+    expect(pts.length).toBe(32); // halbe Ellipse = 64/2
+  });
+
+  it('Winkel-Metadaten in properties', () => {
+    const { ctx, doc } = mkCtx({ startAngle: 45, endAngle: 225 });
+    ellipseTool.handlers.down!(pe(0, 0), ctx);
+    ellipseTool.handlers.down!(pe(100, 0), ctx);
+    ellipseTool.handlers.down!(pe(0, 50), ctx);
+    const el = doc.getAllElements()[0];
+    expect(el.properties.startAngle).toBe(45);
+    expect(el.properties.endAngle).toBe(225);
+  });
+});
+
+describe('D1: Manifest', () => {
+  it('id=ellipse, ribbonTab=canvas, tags basic, Version in tools-Array', () => {
+    expect(ellipseTool.manifest.id).toBe('ellipse');
+    expect(ellipseTool.manifest.ribbonTab).toBe('canvas');
+    expect((ellipseTool.manifest.tags ?? [])).toContain('basic');
+  });
+});

frontend/tests/eventPolish.test.ts

@@ -0,0 +1,106 @@
+/**
+ * Task E7 – Event-Elemente-Polish: curtain, spotlight, barrier,
+ * stage-height-Attribut.
+ *
+ * Prüft die Tool-Platzierung (Element-Form + Options), die
+ * Pixi-Drawer-Primitives und die height-Durchreichung für stage.
+ */
+import { describe, it, expect } from 'vitest';
+import {
+  curtainTool, spotlightTool, barrierTool,
+} from '../src/plugins/builtin/event-tools';
+import { createInMemoryDoc } from './helpers/inMemoryDoc';
+import { CADDocument } from '../src/kernel/document/CADDocument';
+import { elementToPrimitives } from '../src/render/pixi/elementDrawers';
+import { SeatingService } from '../src/services/seatingService';
+import type { CADElement, Pt } from '../src/types/cad.types';
+
+function fireDown(tool: any, world: Pt, options: Record<string, unknown> = {}) {
+  const { ydoc } = createInMemoryDoc();
+  const doc = new CADDocument(ydoc);
+  const ctx = {
+    doc,
+    options,
+    setStatus: () => {},
+    setPreview: () => {},
+  } as any;
+  tool.handlers.down({ world } as any, ctx);
+  return { added: doc.getAllElements(), doc };
+}
+
+describe('E7: curtain', () => {
+  it('curtainTool platziert curtain-Element mit Wellen-Polyline und stageHeight', () => {
+    const { added } = fireDown(curtainTool, { x: 100, y: 50 }, { stageHeight: 120 });
+    expect(added.length).toBe(1);
+    const el = added[0];
+    expect(el.type).toBe('curtain');
+    expect(el.width).toBe(400); // Standard-Breite
+    expect(el.properties.stageHeight).toBe(120);
+    const pts = el.properties.points as Pt[];
+    expect(Array.isArray(pts)).toBe(true);
+    expect(pts.length).toBeGreaterThan(20); // Wellenpunkte
+  });
+
+  it('Drawer: curtain → polyline-Primitive (geschlossen=false)', () => {
+    const { added } = fireDown(curtainTool, { x: 100, y: 50 }, { stageHeight: 120 });
+    const prims = elementToPrimitives(added[0]);
+    expect(prims.length).toBe(1);
+    expect(prims[0].kind).toBe('polyline');
+    expect((prims[0] as any).close).toBe(false);
+  });
+});
+
+describe('E7: spotlight', () => {
+  it('spotlightTool platziert Lichtkegel-Polygon mit angle und color', () => {
+    const { added } = fireDown(spotlightTool, { x: 0, y: 0 }, { angle: 45, color: '#ffcc00' });
+    expect(added.length).toBe(1);
+    const el = added[0];
+    expect(el.type).toBe('spotlight');
+    expect(el.properties.angle).toBe(45);
+    expect(el.properties.color).toBe('#ffcc00');
+    const pts = el.properties.points as Pt[];
+    expect(pts.length).toBe(4); // Kegel: Ursprung + zwei Basis-Ecken + zurück
+  });
+
+  it('Drawer: spotlight → Polygon mit Füllung aus color', () => {
+    const { added } = fireDown(spotlightTool, { x: 0, y: 0 }, { angle: 45, color: '#ffcc00' });
+    const prims = elementToPrimitives(added[0]);
+    expect(prims.length).toBe(1);
+    expect(prims[0].kind).toBe('polyline');
+    expect((prims[0] as any).close).toBe(true);
+    expect((prims[0] as any).stroke.toLowerCase()).toContain('#ffcc00');
+  });
+
+  it('Kegel-Ausrichtung: angle=0 zeigt nach rechts (Richtung +x)', () => {
+    const { added } = fireDown(spotlightTool, { x: 0, y: 0 }, { angle: 0, color: '#fff' });
+    const pts = added[0].properties.points as Pt[];
+    expect(pts[1].x).toBeGreaterThan(100); // Basis-Ecke weiter rechts als Ursprung
+    expect(pts[2].x).toBeGreaterThan(100);
+  });
+});
+
+describe('E7: barrier', () => {
+  it('barrierTool platziert Kette aus Kreis-Paaren entlang Standardlänge', () => {
+    const { added } = fireDown(barrierTool, { x: 0, y: 0 }, {});
+    expect(added.length).toBe(1);
+    const el = added[0];
+    expect(el.type).toBe('barrier');
+    expect(el.width).toBe(200); // Standard-Länge
+  });
+
+  it('Drawer: barrier → mehrere circle-Primitives (Kettenglieder)', () => {
+    const { added } = fireDown(barrierTool, { x: 0, y: 0 }, {});
+    const prims = elementToPrimitives(added[0]);
+    expect(prims.length).toBeGreaterThan(4);
+    expect(prims.every((p) => p.kind === 'circle')).toBe(true);
+  });
+});
+
+describe('E7: stage height', () => {
+  it('createStage nimmt height-Option auf (properties.height)', () => {
+    const stage = new SeatingService().createStage(100, 100, 'layer-0', { width: 400, height: 60 });
+    expect(stage.type).toBe('stage');
+    expect(stage.properties.height).toBe(60);
+    expect(stage.width).toBe(400);
+  });
+});

frontend/tests/geometry.test.ts

@@ -10,6 +10,9 @@ import {
   offsetElement,
   getElementBBox,
   distance,
+  lineCircleIntersections,
+  circleCircleIntersections,
+  lineArcIntersection,
   angleBetween,
 } from '../src/tools/modification/geometry';
 import type { CADElement } from '../src/types/cad.types';
@@ -293,3 +296,90 @@ describe('geometry – angleBetween', () => {
     expect(angleBetween({ x: 0, y: 0 }, { x: 0, y: 100 })).toBe(90);
   });
 });
+
+describe('geometry – lineCircleIntersections', () => {
+  const p1 = { x: 0, y: 0 };
+  const p2 = { x: 200, y: 0 };
+  const c = { x: 100, y: 0 };
+
+  it('findet zwei Schnittpunkte bei Sekante', () => {
+    const pts = lineCircleIntersections(p1, p2, c, 40);
+    expect(pts.length).toBe(2);
+    const xs = pts.map((p) => Math.round(p.x)).sort((a, b) => a - b);
+    expect(xs).toEqual([60, 140]);
+  });
+
+  it('findet genau einen Punkt bei Tangente', () => {
+    // Strecke entlang y=40 tangiert Kreis (100,0,r=40)
+    const pts = lineCircleIntersections({ x: 50, y: 40 }, { x: 150, y: 40 }, { x: 100, y: 0 }, 40);
+    expect(pts.length).toBe(1);
+    expect(pts[0].x).toBeCloseTo(100);
+    expect(pts[0].y).toBeCloseTo(40);
+  });
+
+  it('liefert leeres Array ohne Schnitt (Diskriminante < 0)', () => {
+    expect(lineCircleIntersections(p1, p2, { x: 100, y: 500 }, 10)).toEqual([]);
+  });
+
+  it('respektiert Segmentgrenzen t∈[0,1] (Verlaengerung schneidet nicht)', () => {
+    // Kreis liegt hinter dem Endpunkt der Strecke
+    expect(lineCircleIntersections({ x: 0, y: 0 }, { x: 50, y: 0 }, { x: 100, y: 0 }, 30)).toEqual([]);
+  });
+});
+
+describe('geometry – circleCircleIntersections', () => {
+  it('findet zwei Punkte bei Ueberlappung', () => {
+    const pts = circleCircleIntersections({ x: 0, y: 0 }, 50, { x: 80, y: 0 }, 50);
+    expect(pts.length).toBe(2);
+    for (const pt of pts) {
+      expect(pt.x).toBeCloseTo(40);           // Symmetrieachse
+      expect(Math.abs(pt.y)).toBeCloseTo(30); // Höhe via Satz des Pythagoras
+    }
+  });
+
+  it('liefert einen Punkt bei Tangenz', () => {
+    const pts = circleCircleIntersections({ x: 0, y: 0 }, 50, { x: 100, y: 0 }, 50);
+    expect(pts.length).toBe(1);
+    expect(pts[0]).toEqual({ x: 50, y: 0 });
+  });
+
+  it('liefert leer bei getrennten Kreisen und identischen Zentren', () => {
+    expect(circleCircleIntersections({ x: 0, y: 0 }, 20, { x: 500, y: 0 }, 20)).toEqual([]);
+    expect(circleCircleIntersections({ x: 0, y: 0 }, 20, { x: 0, y: 0 }, 20)).toEqual([]);
+  });
+});
+
+describe('geometry – lineArcIntersection', () => {
+  function makeArc(id: string, cx: number, cy: number, r: number, startDeg: number, endDeg: number): CADElement {
+    return {
+      id,
+      type: 'arc',
+      layerId: 'layer-1',
+      x: cx,
+      y: cy,
+      width: r * 2,
+      height: r * 2,
+      properties: { radius: r, startAngle: startDeg, endAngle: endDeg },
+    } as unknown as CADElement;
+  }
+
+  it('schneidet Strecke mit Halbkreis (0°..180°)', () => {
+    const arc = makeArc('a1', 100, 0, 40, 0, 180); // obere Hälfte (CCW von 3Uhr)
+    const pts = lineArcIntersection({ x: 60, y: 0 }, { x: 140, y: 40 }, arc);
+    // Linie von (60,0) nach (140,40): schneidet Bogen einmal oben
+    expect(pts.length).toBeGreaterThanOrEqual(1);
+  });
+
+  it('filtert Treffer außerhalb des Winkelbereichs heraus', () => {
+    const arc = makeArc('a2', 100, 0, 40, 180, 360); // untere Hälfte
+    // Strecke verläuft komplett oberhalb der Mittellinie → Schnitte lägen nur
+    // im oberen Halbkreis (Winkel < 180°), der nicht Teil des Bogens ist.
+    const pts = lineArcIntersection({ x: 60, y: 20 }, { x: 140, y: 40 }, arc);
+    expect(pts).toEqual([]);
+  });
+
+  it('liefert leer bei fehlendem Radius (ungueltiges Element)', () => {
+    const bad = { id: 'x', type: 'arc', layerId: 'l', x: 0, y: 0, width: 0, height: 0, properties: {} } as unknown as CADElement;
+    expect(lineArcIntersection({ x: -10, y: -10 }, { x: 10, y: 10 }, bad)).toEqual([]);
+  });
+});

frontend/tests/gripEditing.test.ts

@@ -0,0 +1,244 @@
+/**
+ * Task D9 – GripEditing: Vertex-/Center-Grips im select-Tool.
+ *
+ * getGripPoints: element-spezifische Griff-Punkte (line=Endpunkte,
+ * polyline=Vertices, circle/arc=Zentrum, rect=BBox-Ecken).
+ * Drag eines Vertex-Grips verschiebt NUR diesen Punkt in einer
+ * Transaktion (undo-fähig); BBox-Skalierung (C3fin) bleibt parallel
+ * für Elemente ohne Vertex-Grips (rect u.a.).
+ */
+import { describe, it, expect, beforeEach } from 'vitest';
+import { selectTool, getGripPoints } from '../src/plugins/builtin/core-modify';
+import { CADDocument } from '../src/kernel/document/CADDocument';
+import { createInMemoryDoc } from './helpers/inMemoryDoc';
+import type { CADElement, Pt } from '../src/types/cad.types';
+
+function mkCtx() {
+  const { ydoc } = createInMemoryDoc();
+  const doc = new CADDocument(ydoc);
+  const selectedIds = new Set<string>();
+  const previews: (CADElement | null)[] = [];
+  const statuses: string[] = [];
+  const ctx: any = {
+    doc,
+    options: {},
+    setStatus: (m: string) => statuses.push(m),
+    setPreview: (el: CADElement | null) => previews.push(el),
+    selection: {
+      getIds: () => Array.from(selectedIds),
+      setIds: (ids: string[]) => {
+        selectedIds.clear();
+        for (const id of ids) selectedIds.add(id);
+      },
+      hitTest: (x: number, y: number, tol: number) => {
+        // Einfacher Hit-Test: trifft wenn ein Element-BBox den Punkt enthaelt
+        for (const el of doc.getAllElements()) {
+          const p = el.properties as Record<string, unknown>;
+          if (p.x1 !== undefined) {
+            const minX = Math.min(p.x1 as number, p.x2 as number);
+            const maxX = Math.max(p.x1 as number, p.x2 as number);
+            const minY = Math.min(p.y1 as number, p.y2 as number);
+            const maxY = Math.max(p.y1 as number, p.y2 as number);
+            if (x >= minX - tol && x <= maxX + tol && y >= minY - tol && y <= maxY + tol) return el;
+          }
+          if (x >= el.x - el.width / 2 - tol && x <= el.x + el.width / 2 + tol &&
+              y >= el.y - el.height / 2 - tol && y <= el.y + el.height / 2 + tol) return el;
+        }
+        return null;
+      },
+    },
+  };
+  return { ctx, doc, selectedIds, previews, statuses };
+}
+
+function pe(x: number, y: number, mods: { shift?: boolean; ctrl?: boolean } = {}): { world: Pt; shift: boolean; ctrl: boolean } {
+  return { world: { x, y }, shift: mods.shift ?? false, ctrl: mods.ctrl ?? false } as never;
+}
+
+beforeEach(() => {
+  selectTool.handlers.cancel?.({ setStatus: () => {}, setPreview: () => {} } as never);
+});
+
+// ─── getGripPoints (reine Funktion) ────────────────────────
+
+describe('D9: getGripPoints', () => {
+  it('line: beide Endpunkte als Grips', () => {
+    const el = {
+      id: 'l1', type: 'line', layerId: 'l', x: 50, y: 50, width: 100, height: 0,
+      properties: { x1: 0, y1: 50, x2: 100, y2: 50 },
+    } as unknown as CADElement;
+    const grips = getGripPoints(el);
+    expect(grips.map((g) => g.kind)).toEqual(['vertex', 'vertex']);
+    expect(grips[0].point).toEqual({ x: 0, y: 50 });
+    expect(grips[1].point).toEqual({ x: 100, y: 50 });
+  });
+
+  it('polyline: alle Vertices als Grips', () => {
+    const el = {
+      id: 'p1', type: 'polyline', layerId: 'l', x: 50, y: 0, width: 100, height: 100,
+      properties: { points: [{ x: 0, y: 0 }, { x: 100, y: 0 }, { x: 100, y: 100 }] },
+    } as unknown as CADElement;
+    const grips = getGripPoints(el);
+    expect(grips.length).toBe(3);
+    expect(grips.every((g) => g.kind === 'vertex')).toBe(true);
+    expect(grips[2].point).toEqual({ x: 100, y: 100 });
+  });
+
+  it('circle: Zentrum als Center-Grip', () => {
+    const el = {
+      id: 'c1', type: 'circle', layerId: 'l', x: 30, y: 40, width: 20, height: 20,
+      properties: { radius: 10 },
+    } as unknown as CADElement;
+    const grips = getGripPoints(el);
+    expect(grips).toHaveLength(1);
+    expect(grips[0].kind).toBe('center');
+    expect(grips[0].point).toEqual({ x: 30, y: 40 });
+  });
+
+  it('rect: BBox-Ecken als Corner-Grips (C3fin bleibt)', () => {
+    const el = {
+      id: 'r1', type: 'rect', layerId: 'l', x: 50, y: 25, width: 100, height: 50,
+      properties: {},
+    } as unknown as CADElement;
+    const grips = getGripPoints(el);
+    expect(grips.length).toBe(4);
+    expect(grips.every((g) => g.kind === 'corner')).toBe(true);
+    expect(grips[0].point).toEqual({ x: 0, y: 0 });
+    expect(grips[2].point).toEqual({ x: 100, y: 50 });
+  });
+
+  it('Grips tragen index fuer Drag-Zuordnung', () => {
+    const el = {
+      id: 'p1', type: 'polyline', layerId: 'l', x: 0, y: 0, width: 10, height: 10,
+      properties: { points: [{ x: 0, y: 0 }, { x: 10, y: 10 }] },
+    } as unknown as CADElement;
+    const grips = getGripPoints(el);
+    expect(grips[0].index).toBe(0);
+    expect(grips[1].index).toBe(1);
+  });
+});
+
+// ─── Drag-Interaktion: Vertex-Zug (undo-faehig) ─────────────
+
+describe('D9: Vertex-Drag im selectTool', () => {
+  it('Linien-Endpunkt ziehen verschiebt NUR diesen Punkt (1 Undo)', () => {
+    const { ctx, doc, selectedIds } = mkCtx();
+    const line = {
+      id: 'l1', type: 'line', layerId: 'l', x: 50, y: 0, width: 100, height: 0,
+      properties: { x1: 0, y1: 0, x2: 100, y2: 0 },
+    } as unknown as CADElement;
+    doc.addElement(line);
+    selectedIds.add('l1');
+
+    // Klick auf Endpunkt (100,0) startet Vertex-Drag
+    selectTool.handlers.down!(pe(100, 0), ctx);
+    selectTool.handlers.up!(pe(120, 30), ctx);
+
+    const updated = doc.getElement('l1')!;
+    expect(updated.properties.x2).toBe(120);
+    expect(updated.properties.y2).toBe(30);
+    // Anderer Endpunkt unveraendert
+    expect(updated.properties.x1).toBe(0);
+    expect(updated.properties.y1).toBe(0);
+    // Undo stellt her
+    doc.undo();
+    const restored = doc.getElement('l1')!;
+    expect(restored.properties.x2).toBe(100);
+    expect(restored.properties.y2).toBe(0);
+  });
+
+  it('Polyline-Vertex ziehen aktualisiert nur diesen Vertex', () => {
+    const { ctx, doc, selectedIds } = mkCtx();
+    const poly = {
+      id: 'p1', type: 'polyline', layerId: 'l', x: 50, y: 50, width: 100, height: 100,
+      properties: { points: [{ x: 0, y: 0 }, { x: 100, y: 0 }, { x: 100, y: 100 }] },
+    } as unknown as CADElement;
+    doc.addElement(poly);
+    selectedIds.add('p1');
+
+    // Mittleren Vertex (100,0) greifen und auf (100,50) ziehen
+    selectTool.handlers.down!(pe(100, 0), ctx);
+    selectTool.handlers.up!(pe(100, 50), ctx);
+
+    const pts = doc.getElement('p1')!.properties.points as Pt[];
+    expect(pts[1]).toEqual({ x: 100, y: 50 });
+    expect(pts[0]).toEqual({ x: 0, y: 0 });
+    expect(pts[2]).toEqual({ x: 100, y: 100 });
+  });
+
+  it('Kreis-Zentrum ziehen verschiebt x/y (Radius bleibt)', () => {
+    const { ctx, doc, selectedIds } = mkCtx();
+    const circle = {
+      id: 'c1', type: 'circle', layerId: 'l', x: 30, y: 40, width: 20, height: 20,
+      properties: { radius: 10 },
+    } as unknown as CADElement;
+    doc.addElement(circle);
+    selectedIds.add('c1');
+
+    selectTool.handlers.down!(pe(30, 40), ctx);
+    selectTool.handlers.up!(pe(60, 80), ctx);
+
+    const updated = doc.getElement('c1')!;
+    expect(updated.x).toBe(60);
+    expect(updated.y).toBe(80);
+    expect(updated.properties.radius).toBe(10);
+  });
+
+  it('BBox-Corner-Drag bei rect funktioniert weiterhin (Skalierung)', () => {
+    const { ctx, doc, selectedIds } = mkCtx();
+    const rect = {
+      id: 'r1', type: 'rect', layerId: 'l', x: 50, y: 25, width: 100, height: 50,
+      properties: {},
+    } as unknown as CADElement;
+    doc.addElement(rect);
+    selectedIds.add('r1');
+
+    // Ecke unten-rechts (100,50) greifen und auf (150,75) ziehen
+    selectTool.handlers.down!(pe(100, 50), ctx);
+    selectTool.handlers.up!(pe(150, 75), ctx);
+
+    const updated = doc.getElement('r1')!;
+    expect(updated.width).toBeCloseTo(150, 0);
+    expect(updated.height).toBeCloseTo(75, 0);
+  });
+
+  it('Vertex-Grip gewinnt gegen BBox-Corner bei Ueberlappung (line-Endpunkt am BBox-Rand)', () => {
+    // line (0,0)-(100,0): Endpunkt (0,0) ist AUCH BBox-Ecke.
+    // Der Drag muss als Vertex (Punkt verschieben) wirken, nicht als Scale.
+    const { ctx, doc, selectedIds } = mkCtx();
+    const line = {
+      id: 'l1', type: 'line', layerId: 'l', x: 50, y: 0, width: 100, height: 0,
+      properties: { x1: 0, y1: 0, x2: 100, y2: 0 },
+    } as unknown as CADElement;
+    doc.addElement(line);
+    selectedIds.add('l1');
+
+    selectTool.handlers.down!(pe(0, 0), ctx);
+    selectTool.handlers.up!(pe(-30, -20), ctx);
+
+    const updated = doc.getElement('l1')!;
+    // x1/y1 verschoben, x2 unveraendert → Vertex-Drag, kein Scale
+    expect(updated.properties.x1).toBe(-30);
+    expect(updated.properties.y1).toBe(-20);
+    expect(updated.properties.x2).toBe(100);
+  });
+
+  it('Preview bei Vertex-Drag zeigt aktualisiertes Element', () => {
+    const { ctx, doc, selectedIds, previews } = mkCtx();
+    const line = {
+      id: 'l1', type: 'line', layerId: 'l', x: 50, y: 0, width: 100, height: 0,
+      properties: { x1: 0, y1: 0, x2: 100, y2: 0 },
+    } as unknown as CADElement;
+    doc.addElement(line);
+    selectedIds.add('l1');
+
+    selectTool.handlers.down!(pe(100, 0), ctx);
+    selectTool.handlers.move!(pe(90, 40), ctx);
+    expect(previews.length).toBeGreaterThanOrEqual(1);
+    const last = previews[previews.length - 1];
+    expect(last).not.toBeNull();
+    const lastProps = last!.properties as Record<string, unknown>;
+    expect(lastProps.x2).toBe(90);
+    expect(lastProps.y2).toBe(40);
+  });
+});

frontend/tests/helpers.smoke.test.ts

@@ -0,0 +1,74 @@
+/**
+ * Smoke-Tests für die Test-Helfer aus Task A0.
+ * Stellt sicher, dass Logger, MockRenderEngine und InMemoryDoc funktionieren,
+ * BEVOR spätere Tasks auf ihnen aufbauen.
+ */
+import { describe, it, expect, vi } from 'vitest';
+import { logger, setLogLevel } from '../src/utils/logger';
+import { MockRenderEngine } from './helpers/mockAdapter';
+import { createInMemoryDoc, makeTestLayer } from './helpers/inMemoryDoc';
+import type { CADElement } from '../src/types/cad.types';
+
+describe('A0 helpers – logger', () => {
+  it('schreibt info im Default-Level in die Testumgebung', () => {
+    const spy = vi.spyOn(console, 'log').mockImplementation(() => {});
+    setLogLevel('info');
+    logger.info('smoke test message');
+    expect(spy).toHaveBeenCalledWith('[web-cad]', 'smoke test message');
+    spy.mockRestore();
+  });
+
+  it('debug bleibt bei Level info still und erscheint bei debug', () => {
+    const spy = vi.spyOn(console, 'log').mockImplementation(() => {});
+    setLogLevel('info');
+    logger.debug('hidden');
+    expect(spy).not.toHaveBeenCalled();
+    setLogLevel('debug');
+    logger.debug('visible');
+    expect(spy).toHaveBeenCalledWith('[web-cad][debug]', 'visible');
+    spy.mockRestore();
+  });
+});
+
+describe('A0 helpers – MockRenderEngine', () => {
+  it('protokolliert Aufrufe mit Reihenfolge und Argumenten', () => {
+    const mock = new MockRenderEngine();
+    mock.render();
+    mock.hitTest(10, 20, 5);
+    mock.setPreviewElement(null);
+
+    expect(mock.countCalls('render')).toBe(1);
+    expect(mock.countCalls('hitTest')).toBe(1);
+    expect(mock.lastArgsOf('hitTest')).toEqual([10, 20, 5]);
+    expect(mock.calls.map((c) => c.method)).toEqual(['render', 'hitTest', 'setPreviewElement']);
+  });
+
+  it('liefert konfigurierbare hitTest-Ergebnisse', () => {
+    const mock = new MockRenderEngine();
+    const el = { id: 'e1', type: 'line' } as unknown as CADElement;
+    mock.nextHitTestResult = el;
+    expect(mock.hitTest(0, 0)).toBe(el);
+    mock.reset();
+    expect(mock.hitTest(0, 0)).toBeNull();
+  });
+});
+
+describe('A0 helpers – createInMemoryDoc', () => {
+  it('erstellt netzwerkfreies Dokument mit Seeding', () => {
+    const { ydoc, addAll } = createInMemoryDoc();
+    ydoc.data.layers.set('layer-1', makeTestLayer() as never);
+    const el = { id: 'el1', type: 'rect', layerId: 'layer-1', x: 0, y: 0, width: 1, height: 1, properties: {} } as unknown as CADElement;
+    addAll([el]);
+    expect(ydoc.getElements().length).toBe(1);
+    expect(ydoc.getLayers().length).toBe(1);
+  });
+
+  it('clear entfernt alle Elemente', () => {
+    const { ydoc, addAll, clear } = createInMemoryDoc();
+    const el = { id: 'el1', type: 'rect', layerId: 'layer-1', x: 0, y: 0, width: 1, height: 1, properties: {} } as unknown as CADElement;
+    addAll([el]);
+    expect(ydoc.getElements().length).toBe(1);
+    clear();
+    expect(ydoc.getElements().length).toBe(0);
+  });
+});

frontend/tests/helpers/inMemoryDoc.ts

@@ -0,0 +1,52 @@
+/**
+ * InMemoryDoc-Helper – Netzwerkfreie YjsDocument-Fabrik für Tests.
+ *
+ * YjsDocument läuft bereits komplett In-Memory (Y.Doc ohne Provider);
+ * dieser Wrapper bietet bequemes Seeding und Reset für isolierte Tests.
+ * Genutzt ab A3 (Tool-Workflow-Tests) und A2b (CADDocument-Tests).
+ */
+import { YjsDocument } from '../../src/crdt/YjsDocument';
+import type { CADElement } from '../../src/types/cad.types';
+
+export interface SeededDoc {
+  ydoc: YjsDocument;
+  /** Fügt Elemente in EINER Transaktion hinzu (1 Undo-Schritt). */
+  addAll(elements: CADElement[]): void;
+  /** Entfernt alle Elemente/Layer-Inhalte (Dokument bleibt verwendbar). */
+  clear(): void;
+}
+
+/** Erzeugt ein frisches, leeres Test-Dokument. */
+export function createInMemoryDoc(): SeededDoc {
+  const ydoc = new YjsDocument();
+  return {
+    ydoc,
+    addAll(elements) {
+      ydoc.doc.transact(() => {
+        for (const el of elements) ydoc.data.elements.set(el.id, el);
+      });
+    },
+    clear() {
+      ydoc.doc.transact(() => {
+        for (const id of Array.from(ydoc.data.elements.keys())) {
+          ydoc.data.elements.delete(id);
+        }
+      });
+    },
+  };
+}
+
+/** Basis-CADLayer für Tests. */
+export function makeTestLayer(id = 'layer-1', name = 'Test-Layer') {
+  return {
+    id,
+    name,
+    visible: true,
+    locked: false,
+    color: '#ffffff',
+    lineType: 'solid',
+    transparency: 0,
+    sortOrder: 0,
+    parentId: null,
+  };
+}

frontend/tests/helpers/mockAdapter.ts

@@ -0,0 +1,69 @@
+/**
+ * MockAdapter – Headless-Doppel der RenderEngine für Workflow-Tests.
+ * Zeichnet nichts; protokolliert alle Aufrufe in `calls` (Reihenfolge getreu).
+ *
+ * Methodenumfang = genau das, was InteractionEngine derzeit an RenderEngine
+ * ruft (verifiziert in Task A0): hitTest, render, setActiveSnapPoint,
+ * setOptions, setPreviewElement, setSnapPoints.
+ * Wird in C1 (RenderAdapter-Interface) um die vollen Adapter-Methoden erweitert.
+ */
+import type { CADElement } from '../../src/types/cad.types';
+
+export interface RecordedCall {
+  method: string;
+  args: unknown[];
+}
+
+export class MockRenderEngine {
+  /** Alle Aufrufe in Reihenfolge. */
+  readonly calls: RecordedCall[] = [];
+
+  /** Von Tests konfigurierbare hitTest-Rückgabe. */
+  nextHitTestResult: CADElement | null = null;
+
+  // ── Von InteractionEngine genutzte Fläche ────────────────
+
+  hitTest(x: number, y: number, tolerance?: number): CADElement | null {
+    this.calls.push({ method: 'hitTest', args: [x, y, tolerance] });
+    return this.nextHitTestResult;
+  }
+
+  render(): void {
+    this.calls.push({ method: 'render', args: [] });
+  }
+
+  setActiveSnapPoint(pt: unknown): void {
+    this.calls.push({ method: 'setActiveSnapPoint', args: [pt] });
+  }
+
+  setOptions(opts: Record<string, unknown>): void {
+    this.calls.push({ method: 'setOptions', args: [opts] });
+  }
+
+  setPreviewElement(el: CADElement | null): void {
+    this.calls.push({ method: 'setPreviewElement', args: [el] });
+  }
+
+  setSnapPoints(pts: unknown[]): void {
+    this.calls.push({ method: 'setSnapPoints', args: [pts] });
+  }
+
+  // ── Test-Helfer ──────────────────────────────────────────
+
+  /** Anzahl Aufrufe einer Methode. */
+  countCalls(method: string): number {
+    return this.calls.filter((c) => c.method === method).length;
+  }
+
+  /** Letzte aufgezeichnete Argumentliste einer Methode (oder undefined). */
+  lastArgsOf(method: string): unknown[] | undefined {
+    const found = this.calls.filter((c) => c.method === method);
+    return found.length ? found[found.length - 1].args : undefined;
+  }
+
+  /** Protokoll leeren. */
+  reset(): void {
+    this.calls.length = 0;
+    this.nextHitTestResult = null;
+  }
+}

frontend/tests/i18n.test.tsx

@@ -0,0 +1,93 @@
+/**
+ * Task H4 – i18n-Grundlage: zentrale strings.ts Maps de/en.
+ *
+ * strings-Modul: t(key) mit de/en-Maps, getLanguage/setLanguage
+ * (localStorage-persistiert, Default de), subscribe + useT-Hook.
+ * Kern-UI-Texte (LayoutBar, Modus-Umschaltung) laufen ueber die
+ * Maps; vollstaendige mechanische Ersetzung aller Komponenten ist
+ * teilautomatisierbares Follow-up (Roadmap-Vermerk).
+ */
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import { render, screen, cleanup, fireEvent, act } from '@testing-library/react';
+import {
+  t, getLanguage, setLanguage, subscribeLanguage, useT, LANGUAGES,
+} from '../src/i18n/strings';
+
+afterEach(cleanup);
+
+// ––– strings-Modul ––––––––––––––––––––––––
+
+describe('H4: i18n strings', () => {
+  beforeEach(() => {
+    localStorage.clear();
+    setLanguage('de');
+  });
+
+  it('Default-Sprache ist de', () => {
+    expect(getLanguage()).toBe('de');
+  });
+
+  it('t liefert deutsche Kern-UI-Texte', () => {
+    expect(t('layouts.title')).toBe('Layouts');
+    expect(t('layouts.add')).toBe('Layout hinzufügen');
+    expect(t('layouts.empty')).toBe('Keine Layouts');
+  });
+
+  it('setLanguage(en) wechselt auf englische Texte', () => {
+    setLanguage('en');
+    expect(t('layouts.title')).toBe('Layouts');
+    expect(t('layouts.add')).toBe('Add layout');
+    expect(t('layouts.empty')).toBe('No layouts');
+  });
+
+  it('Sprache persistiert in localStorage und ueberlebt Reload-Semantik', () => {
+    setLanguage('en');
+    expect(localStorage.getItem('webcad.language')).toBe('en');
+    // erneutes Lesen startet aus persistiertem Zustand
+    expect(getLanguage()).toBe('en');
+  });
+
+  it('LANGUAGES enthaelt genau de und en', () => {
+    expect(LANGUAGES).toEqual(['de', 'en']);
+  });
+
+  it('t mit unbekanntem Key liefert den Key zurueck (Fallback, lint-bar)', () => {
+    setLanguage('de');
+    expect(t('gibts.nicht')).toBe('gibts.nicht');
+  });
+
+  it('subscribeLanguage feuert bei Wechsel und unsubscribed', () => {
+    const cb = vi.fn();
+    const off = subscribeLanguage(cb);
+    setLanguage('en');
+    expect(cb).toHaveBeenCalledWith('en');
+    off();
+    cb.mockClear();
+    setLanguage('de');
+    expect(cb).not.toHaveBeenCalled();
+  });
+});
+
+// ––– useT-Hook + Komponente ––––––––––––––––––
+
+describe('H4: useT-Hook rendert LayoutBar zweisprachig', () => {
+  beforeEach(() => {
+    localStorage.clear();
+    setLanguage('de');
+  });
+
+  it('LayoutBar zeigt deutsche Texte und wechselt live auf englisch', async () => {
+    const LayoutBar = (await import('../src/components/LayoutBar')).default;
+    render(<LayoutBar doc={null} bridge={null} />);
+    expect(screen.getByText('Layouts')).toBeTruthy();
+    expect(screen.getByText('Keine Layouts')).toBeTruthy();
+    expect(screen.getByTitle('Layout hinzufügen')).toBeTruthy();
+
+    act(() => {
+      setLanguage('en');
+    });
+    // Live-Update via subscribe (nach act flush)
+    expect(screen.getByText('No layouts')).toBeTruthy();
+    expect(screen.getByTitle('Add layout')).toBeTruthy();
+  });
+});