feat: 切换对话时恢复对应的Agent显示

main_v2.py

@@ -546,14 +546,20 @@ async def websocket_endpoint(websocket: WebSocket, user_id: str):
                     
                     if conversation:
                         messages = conv_service.get_messages(conversation.id)
+                        
+                        # 获取对话使用的Agent ID
+                        conv_agent_id = conversation.current_agent_id
+                        
                         await websocket.send_json({
                             "type": "history",
                             "conversation_id": current_conversation_id,
+                            "agent_id": conv_agent_id,  # 返回对话的Agent ID
                             "messages": [
                                 {
                                     "role": m.role,
                                     "content": m.content,
                                     "thinking_content": m.thinking_content,
+                                    "agent_id": m.agent_id,  # 每条消息的Agent ID
                                     "source": m.source,
                                     "created_at": m.created_at.isoformat()
                                 }