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/plugins/builtins/kommunikation/websocket_manager.py

@@ -8,6 +8,7 @@ import uuid
 from typing import Any
 
 from fastapi import WebSocket
+from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.core.ws_helpers import (
     authenticate_ws,
@@ -21,7 +22,6 @@ from app.core.ws_pubsub import (
     get_tenant_channel,
     subscribe_to_channel,
 )
-from sqlalchemy.ext.asyncio import AsyncSession
 
 logger = logging.getLogger(__name__)
 
@@ -106,7 +106,7 @@ class WebSocketManager:
 
         # Remove from subscriptions if no more connections
         if user_id not in self._connections:
-            for conv_id, users in self._subscriptions.items():
+            for _conv_id, users in self._subscriptions.items():
                 users.discard(user_id)
 
         logger.debug(f"WebSocket disconnected: user={user_id}")