Security fixes: P0-P2 complete (22 fixes)

P0 (7): Auth-bypass removed, migrations fixed, plugin-upload disabled, RLS FORCE+WITH CHECK, plugin double-registration fixed, persistent volume, domain removed
P1 (11): User/tenant model, Redis centralized, worker separated, transactional outbox, XSS fixed, DMS chunked streaming, permissions unified, password reset, metrics secured, config/docs fixed, cross-tenant FK
P2 (4): Contact model normalized, cross-imports reduced 94%, commands+state machines for contacts/dms/mail/calendar, SPA path-traversal

8 new migrations, 99 unit tests, 13 commands, 8 contracts, 72 files changed

app/plugins/builtins/kommunikation/dms_bridge.py

@@ -13,7 +13,10 @@ from fastapi import UploadFile
 from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 
-from app.plugins.builtins.dms.models import File as DmsFile, Folder
+from app.plugins.builtins.dms.contracts import get_contract as get_dms_contract
+_dms = get_dms_contract()
+DmsFile = _dms.DmsFile
+Folder = _dms.Folder
 
 logger = logging.getLogger(__name__)