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.

tests/conftest.py

@@ -77,7 +77,7 @@ for _plugin_name in _registry.list_discovered():
         # every plugin's entity models are registered in ENTITY_MODELS —
         # the core registry itself carries core entities only.
         for _entity_type, _model_class in _entity_models.items():
-            register_entity_model(_entity_type, _model_class)
+            register_entity_model(_entity_type, _model_class, plugin_name=_plugin_name)
         # Also import the plugin's __init__ to ensure all models are loaded
         import importlib
         try:
@@ -105,7 +105,7 @@ def _ensure_plugin_entity_models():
         if _plugin is None:
             continue
         for _entity_type, _model_class in _plugin.get_entity_models().items():
-            register_entity_model(_entity_type, _model_class)
+            register_entity_model(_entity_type, _model_class, plugin_name=_plugin_name)
     yield
 
 # Also import core models that may be missing