fix: 在 echoFull 函数中注册和注销处理器，确保消息返回的 JSON 结构正确

handler/echo/echo.go

@@ -33,8 +33,9 @@ func addEchoFullTrigger(msg model.Message) (reply *model.Reply) {
 
 func echoFull(msg model.Message) (reply *model.Reply, catched bool) {
 	msgBytes, _ := json.Marshal(msg.StructuredMsg)
+	handler.UnRegisterLiveHandler(msg.GroupInfo.GroupId, msg.UserId)
 	return &model.Reply{
-		ReplyMsg:       msgBytes,
+		ReplyMsg:       string(msgBytes),
 		ReferOriginMsg: false,
 		FromMsg:        msg,
 	}, true