✨ feat(db): 根据慢查询统计添加几个索引

shared/db/PrivateMessage.ts

@@ -8,6 +8,7 @@ import { MSG_STATUS } from '../consts';
 @modelOptions({ schemaOptions: { id: false } })
 @index({ roomId: 1, seqId: -1 })
 @index({ msgId: 1 })
+@index({ msgCode: 1 })
 export default class PrivateMessage extends BaseModel {
     @prop({ required: true, default: '' })
     roomId: string; // 频道唯一 Id，由 roleId 和 targetRoleId 排序后拼接