feat: add unified WebSocket connection manager and routing

- Implemented UnifiedWebSocketManager for managing WebSocket connections, including subscription handling and message sending.
- Created unified WebSocket router to handle client messages, including authentication, subscription, and chat session management.
- Added support for logging and plugin progress subscriptions.
- Enhanced error handling and response structure for WebSocket operations.

src/webui/routers/websocket/__init__.py

@@ -1,7 +1,9 @@
+"""WebSocket 路由聚合导出。"""
+
 from .auth import router as ws_auth_router
-from .logs import router as logs_router
+from .unified import router as unified_ws_router
 
 __all__ = [
-    "logs_router",
+    "unified_ws_router",
     "ws_auth_router",
 ]