dto.AddCommentReq

{
    "at": [
        "[\"小明\"",
        "\"小红\"]"
    ],
    "cid": 123456,
    "content": "这是一条评论",
    "parentId": 0,
    "replyContent": "原始评论内容",
    "replyUserId": 123456,
    "replyUserName": "小明"
}