fix: WebSocket 403 — SameSite=Strict blocked session cookie on WS connections

Root cause: session_cookie_samesite was 'strict' which prevents the
browser from sending the session cookie on WebSocket upgrade requests.
Changed to 'lax' which allows WebSocket cookies while still blocking
cross-site POST CSRF attacks.

Also removed debug logging from kommunikation routes.

app/plugins/builtins/kommunikation/routes.py

@@ -471,33 +471,23 @@ async def websocket_endpoint(
 
     Authenticates via session cookie. On connect, subscribes user to all their conversations.
     """
-    import logging as _log
-    _logger = _log.getLogger("websocket_debug")
-    _logger.warning("WS CONNECT START: path=%s headers=%s", websocket.url.path, dict(websocket.headers))
-
     # Verify Origin header against allowed CORS origins
     from app.config import get_settings
     from app.core.auth import get_session_data, get_redis, verify_ws_origin
 
     settings = get_settings()
-    _logger.warning("WS verify_ws_origin result: %s", verify_ws_origin(websocket))
     if not verify_ws_origin(websocket):
-        _logger.warning("WS REJECTED: origin not allowed")
         await websocket.close(code=4003, reason="Origin not allowed")
         return
 
     session_id = websocket.cookies.get(settings.session_cookie_name)
-    _logger.warning("WS session_id: %s", session_id is not None)
     if not session_id:
-        _logger.warning("WS REJECTED: no session cookie")
         await websocket.close(code=4001, reason="Not authenticated")
         return
 
     redis = get_redis()
     session_data = await get_session_data(redis, session_id)
-    _logger.warning("WS session_data: %s", session_data is not None)
     if session_data is None:
-        _logger.warning("WS REJECTED: session expired")
         await websocket.close(code=4001, reason="Session expired")
         return
 
@@ -507,9 +497,7 @@ async def websocket_endpoint(
     # Get WebSocket manager from service container
     from app.core.service_container import get_container
     container = get_container()
-    _logger.warning("WS container has comm_websocket: %s", container.has("comm_websocket"))
     if not container.has("comm_websocket"):
-        _logger.warning("WS REJECTED: comm_websocket not in container. Services: %s", list(container._services.keys()))
         await websocket.close(code=4003, reason="Messaging not available")
         return