fix(audit): P0-P3 audit fixes — 838 ruff errors → 0, 30 F821 bugs fixed, 118 files changed

- P0: hooks.py 3-tuple fix, trigger_dispatcher Contract, contacts/plugin unregister_actions_by_owner
- P0: 5 test files — check_permission mocks removed, hardcoded DB credential → env var
- P1: attachment_service DmsFile via Contract helper, restore_registry/history_hooks dedup
- P1: mail/plugin restore unregister, mcp_client datetime.now(UTC), saved_views/filters patterns
- P1: ProtectedRoute fail-closed, 13 test assertion fixes (bcrypt, DB-URLs, SECRET_KEYs)
- P2: deprecated notifications → post_system_message (3 files), forgejo Base, report_generator lazy import
- P2: webhooks permissions, deps.py/roles.py plugin perms removed, import_export default
- P2: address/tags/entity_links patterns removed, worker.py Contract-Umgehungen fixed
- P2: 28 frontend TODOs (hardcoded constants, deprecated notification API)
- P3: dead code, duplicates, deprecated imports, private attr, __import__ inline
- P3: 8 frontend TODOs (LucideIcons, inline styles, XSS, i18n)
- ruff: 838 → 0 (612 auto-fix + 246 manual + 27 F821 regression fix)
- F821: 30 → 0 (AutomationDefinition, DmsFile, user_id, Path, Any, String)
- Contract-Umgehungen: 2 neue gefunden (worker.py:169, worker.py:280) und gefixt

app/routes/users.py

@@ -6,19 +6,19 @@ import uuid
 from typing import Any
 
 from fastapi import APIRouter, Depends, HTTPException, Query, Response, status
-from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.core.audit import log_audit
 from app.core.auth import get_redis, invalidate_all_user_sessions
 from app.core.db import get_db
-from app.core.notifications import create_notification
+from app.core.notifications import post_system_message
 from app.core.permissions import invalidate_permission_cache
 from app.deps import get_current_user, require_permission
-from app.models.user import User, UserTenant
-from app.schemas.user import UserCreate, UserUpdate, UserResponse, PaginatedUsers
-from app.services.user_service import user_service, _UNSET
+from app.models.user import User
+from app.schemas.user import PaginatedUsers, UserCreate, UserResponse, UserUpdate
 from app.services.owner_transfer_service import transfer_ownership
+from app.services.user_service import _UNSET, user_service
 
 router = APIRouter(prefix="/api/v1/users", tags=["users"])
 
@@ -103,7 +103,7 @@ async def create_user(
     )
 
     # Notification
-    await create_notification(
+    await post_system_message(
         db,
         tenant_id,
         user.id,