feat(skills): UI fuer AI-Skill-Definitionen — Modul 7/16 des UI-Backlogs

Zweites Modul via Phase-Q-Manifest-Architektur: Registrierung komplett
ueber das automation-Plugin-Manifest (page_route /skills + menu_item,
Sparkles-Icon) — routes/index.tsx und Sidebar.tsx unangetastet. Der
Komponenten-Map-Generator wired den lazy import (39 Komponenten).

Backend existierte vollstaendig im automation-Plugin (skill_routes.py:
list mit is_active/category-Filtern, create, get, patch, delete;
automation:read/write/delete), Frontend hatte 0% Abdeckung.

- api/skills.ts: TanStack-Hooks (useSkills mit Filtern, useSkill,
  create/update/delete mit Cache-Invalidierung)
- pages/Skills.tsx: Filter-Tabs (alle/aktiv/inaktiv), Skill-Karten (Name,
  Aktiv/Inaktiv-Badge, Kategorie, Beschreibung, Tool-Count),
  Create/Edit-Dialog (Name, Beschreibung, Instructions-Textarea, Kategorie,
  Tool-IDs als Komma-Liste, Aktiv-Toggle), Delete mit Confirm —
  Create/Edit hinter automation:write, Delete hinter automation:delete
- i18n skills.* + nav.skills de/en

Hinweis: Skills sind Orchestrierungs-Metadaten, KEINE
Berechtigungsquelle — erlaubte Tools verweisen auf Tool-IDs, fuer die
Agent und User bereits berechtigt sein muessen (Backend-Docstring).

Verifikation: Vitest 10/10 (Filter-Tabs, Badges inkl. Inaktiv, Tool-Count,
Create-Flow, Edit prefilled, Delete mit+ohne Confirm, separates
Write/Delete-Gating) · tsc exit 0 · production build exit 0 ·
Backend-Regressionen (route-order, m5-miniapps, n4-scope) 28/28 ·
compileall sauber · Cross-Plugin-Checker 0 · Manifest-Check: page_route
+ menu_item korrekt.

frontend/src/i18n/locales/de.json

@@ -24,7 +24,8 @@
     "systemDashboard": "System Dashboard",
     "approvals": "Freigaben",
     "delegations": "Delegationen",
-    "marketplace": "Marketplace"
+    "marketplace": "Marketplace",
+    "skills": "Skills"
   },
   "auth": {
     "login": "Anmelden",
@@ -1758,5 +1759,34 @@
     "deleteConfirm": "Vorlage '{{name}}' wirklich loeschen?",
     "empty": "Keine Berechtigungs-Vorlagen vorhanden.",
     "loadError": "Vorlagen konnten nicht geladen werden."
+  },
+  "skills": {
+    "title": "Skills",
+    "create": "Skill erstellen",
+    "createTitle": "Neuen Skill definieren",
+    "createSubmit": "Erstellen",
+    "editTitle": "Skill bearbeiten",
+    "save": "Speichern",
+    "name": "Name",
+    "namePlaceholder": "z.B. Rechnungspruefung",
+    "description": "Beschreibung",
+    "descriptionPlaceholder": "Wofuer ist dieser Skill?",
+    "instructions": "Anweisungen",
+    "instructionsPlaceholder": "Schritt-fuer-Schritt-Anweisungen fuer den Agenten...",
+    "category": "Kategorie",
+    "tools": "Erlaubte Tools",
+    "toolsHelper": "Kommagetrennte Tool-IDs. Leer = keine Tools.",
+    "isActive": "Aktiv",
+    "active": "Aktiv",
+    "inactive": "Inaktiv",
+    "filterAll": "Alle",
+    "filterActive": "Aktiv",
+    "filterInactive": "Inaktiv",
+    "toolCount": "{{count}} Tool(s)",
+    "edit": "Bearbeiten",
+    "delete": "Loeschen",
+    "deleteConfirm": "Skill '{{name}}' wirklich loeschen?",
+    "empty": "Keine Skills vorhanden.",
+    "loadError": "Skills konnten nicht geladen werden."
   }
 }

frontend/src/i18n/locales/en.json

@@ -24,7 +24,8 @@
     "systemDashboard": "System Dashboard",
     "approvals": "Approvals",
     "delegations": "Delegations",
-    "marketplace": "Marketplace"
+    "marketplace": "Marketplace",
+    "skills": "Skills"
   },
   "auth": {
     "login": "Sign In",
@@ -1758,5 +1759,34 @@
     "deleteConfirm": "Really delete template '{{name}}'?",
     "empty": "No permission templates yet.",
     "loadError": "Failed to load templates."
+  },
+  "skills": {
+    "title": "Skills",
+    "create": "Create skill",
+    "createTitle": "Define a new skill",
+    "createSubmit": "Create",
+    "editTitle": "Edit skill",
+    "save": "Save",
+    "name": "Name",
+    "namePlaceholder": "e.g. Invoice check",
+    "description": "Description",
+    "descriptionPlaceholder": "What is this skill for?",
+    "instructions": "Instructions",
+    "instructionsPlaceholder": "Step-by-step instructions for the agent...",
+    "category": "Category",
+    "tools": "Allowed tools",
+    "toolsHelper": "Comma-separated tool IDs. Empty = no tools.",
+    "isActive": "Active",
+    "active": "Active",
+    "inactive": "Inactive",
+    "filterAll": "All",
+    "filterActive": "Active",
+    "filterInactive": "Inactive",
+    "toolCount": "{{count}} tool(s)",
+    "edit": "Edit",
+    "delete": "Delete",
+    "deleteConfirm": "Really delete skill '{{name}}'?",
+    "empty": "No skills yet.",
+    "loadError": "Failed to load skills."
   }
 }