add image

packages/cts-api/src/protocol/MsgBase.ts

 import { uuid } from '../utils/uuid';
 
-export type MsgType = 'text' | 'audio' | 'video' | 'cmd' | 'attachment';
+export type MsgType = 'text' | 'audio' | 'video' | 'image' |'cmd' | 'attachment';
 
 export type ChatType = 'chat' | 'room' | 'group' | 'push';