refactor: 优化后端 WebSocket 路由

- 优化 api/routers/websocket.py

Co-authored-by: Cursor <cursoragent@cursor.com>

api/routers/websocket.py

@@ -9,6 +9,7 @@ from enum import Enum
 from typing import Dict
 
 from fastapi import WebSocket, WebSocketDisconnect, HTTPException
+from starlette.websockets import WebSocketState
 from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 
@@ -163,6 +164,9 @@ async def websocket_endpoint(
             # 主循环：处理消息
             while True:
                 try:
+                    if websocket.application_state != WebSocketState.CONNECTED:
+                        logger.info(f"WebSocket 已非连接状态，退出循环: conversation_id={conversation_id}")
+                        break
                     message = await websocket.receive_json()
                     msg_type = message.get("type")
                     
@@ -326,10 +330,14 @@ async def websocket_endpoint(
                         break
                 
                 except RuntimeError as e:
-                    # 检查是否是断开连接相关的错误
+                    # 检查是否是断开连接或未连接状态（如 accept 前/后连接被关闭）
                     error_msg = str(e)
-                    if "disconnect" in error_msg.lower() or "Cannot call \"receive\"" in error_msg:
-                        logger.info(f"WebSocket 连接已断开: conversation_id={conversation_id}")
+                    if (
+                        "disconnect" in error_msg.lower()
+                        or "Cannot call \"receive\"" in error_msg
+                        or "accept" in error_msg.lower() and "not connected" in error_msg.lower()
+                    ):
+                        logger.info(f"WebSocket 连接已断开或未就绪: conversation_id={conversation_id}, error={error_msg}")
                         break
                     else:
                         logger.error(f"处理消息时发生 RuntimeError: {e}", exc_info=True)