优化ChatCallbackEvent事件代码

backend/app/api/routers/request/baseConfig.py

@@ -1,5 +1,7 @@
 from pydantic import BaseModel
 import os
+from enum import Enum
+
 class BaseConfig(BaseModel):
 	projectInfo:str = os.getenv("PROJECT_TITLE","您好，我是博微工程理解小助手，您可以问我有关[线路工程]工程数据的相关问题！")
 
@@ -69,3 +71,10 @@ class BaseConfig(BaseModel):
 		}
 
 
+class ChatEventType(str, Enum):
+    WORKFLOW_START = "workflow_started"
+    WORKFLOW_FINISHED = "workflow_finished"
+    NODE_START = "node_started"
+    NODE_FINISHED = "node_finished"
+    MESSAGE = "message"
+    MESSAGE_END = "message_end"