feat: api add eventtype pong message to avoid api return too slow and frontend ignore it

service/base.ts

@@ -62,9 +62,12 @@ const handleStream = (response: any, onData: IOnData, onCompleted?: IOnCompleted
       const lines = buffer.split('\n')
       try {
         lines.forEach((message) => {
-          if (!message)
+          if (!message || !message.startsWith('data: '))
             return
           bufferObj = JSON.parse(message.substring(6)) // remove data: and parse as json
+          if (bufferObj.event !== 'message')
+            return
+
           onData(unicodeToChar(bufferObj.answer), isFirstMessage, {
             conversationId: bufferObj.conversation_id,
             messageId: bufferObj.id,