fix(arch): externes Audit — 13 Backend-Fixes (Workspace-Modules, Tenant-Manifeste, Lifecycle, Contracts, Permissions)

Verifikation: Alle 17 Audit-Findings gegen den Code geprueft — alle bestaetigt.
Backend-Lifecycle-Fixes umgesetzt; 4 Frontend-Plugin-Architektur-Punkte
als Phase Q in die Roadmap eingeplant.

- P1 list_workspaces: Module + User-Counts gebuendelt laden (Editor-Overwrite-Bug)
- P1 active-manifests: Tenant-Deaktivierung (tenant_plugin_activation) filtern
- P1 uninstall: volle Service-Deactivation VOR registry.uninstall()
- P1 ContractRegistry: DB-Aktivstatus-Guard (Restart-Edge-Case) + Re-Activate
- P1/P2 Field-Definitions: voller Lifecycle (register/unregister) im Service
- P1/P2 Contact-Felddefinitionen (39) ins ContactsPlugin-Manifest verschoben
- P1 12 fehlende Permission-Keys registriert (AST-Scan: 0 fehlend)
- P2 contact_folder -> ContactsPlugin; ENTITY_PLUGIN_OWNERS wird befuellt
- P2 Entity-Permission-Fallback fail-closed statt contacts:read
- P2 forgejo_error_reporter is_core=False; DMS is_core=True (ADR-020)
- P2 Worker: Contacts-Trash-Cleanup ins Plugin (get_job_modules-Discovery)
- P1/P2 DSGVO-Export delegiert an DSAR-Collector (kein Core->Contacts)
- P2 False-green Tests korrigiert (or True, veraltete Route-Count-Assertion)

Verifikation: tests/test_audit_architecture_fixes.py 17/17; Regressionen
gruen (contacts_lifecycle, entity_registry, workspace_scopes, rbac,
lifecycle_service); Combo-Order-Test 35/35; Cross-Plugin-Checker 497/0;
compileall sauber; ruff auf 7-Error-Baseline.

Doku: PROGRESS.md Audit-Section, PLATFORM_ROADMAP.md Phase Q (Q1-Q4),
plugin-development-guide.md Lifecycle, permissions.md Katalog.

app/routes/plugins.py

@@ -58,9 +58,21 @@ async def get_active_manifests(
     dashboard_widgets contributed by each active plugin. Used by the
     frontend PluginRegistry to dynamically register routes, sidebar items,
     settings pages, and detail tabs.
+
+    Audit P1 (tenant manifests): plugins deactivated for the caller's
+    tenant are excluded so UI and API gates agree (no 403-on-click menus).
     """
+    import uuid as uuid_mod
+
     service = get_plugin_service()
-    manifests = await service.get_active_manifests(db)
+    tenant_id: uuid_mod.UUID | None = None
+    raw_tid = current_user.get("tenant_id")
+    if raw_tid:
+        try:
+            tenant_id = uuid_mod.UUID(str(raw_tid))
+        except (ValueError, TypeError):
+            tenant_id = None
+    manifests = await service.get_active_manifests(db, tenant_id=tenant_id)
     return {"plugins": manifests, "total": len(manifests)}