feat: @提及支持改名后链接跟随UID + 显示名自动更新

- comment_mentions新增original_username列，创建时记录原始@用户名
- Mentions map改为{original_username: {uid, name}}结构，name为当前显示名
- 用户改名后：旧@文本仍能匹配original_username，链接跟随uid不变，显示名自动更新
- 前端renderMentions适配新结构

internal/model/comment.go

@@ -25,16 +25,23 @@ type Comment struct {
 	ReplyToName string `gorm:"-:migration;<-:false" json:"reply_to_name,omitempty"`
 	// RepliesCount 回复数（非DB字段，查询填充）
 	RepliesCount int `gorm:"-:migration;<-:false" json:"replies_count,omitempty"`
-	// Mentions 有效@提及映射 username -> uid（非DB字段，批量查询填充）
+	// Mentions 有效@提及映射 original_username -> {uid, 当前显示名}（非DB字段，批量查询填充）
-	// 前端据此判断 @username 是否为有效提及并生成链接
+	// key=创建时的原始@用户名，value={uid,当前显示名}，用户改名后链接仍有效且显示新名
-	Mentions map[string]uint `gorm:"-" json:"mentions,omitempty"`
+	Mentions map[string]MentionInfo `gorm:"-" json:"mentions,omitempty"`
 }
 
-// CommentMention @提及映射（绑定UID，不是username，支持改名后自动更新显示名）
+// CommentMention @提及映射（绑定UID + 原始用户名，支持改名后自动更新显示名）
 type CommentMention struct {
 	ID               uint   `gorm:"primarykey" json:"id"`
 	CommentID        uint   `gorm:"uniqueIndex:idx_comment_uid,priority:1;not null" json:"comment_id"`
 	UID              uint   `gorm:"uniqueIndex:idx_comment_uid,priority:2;not null" json:"uid"`
+	OriginalUsername string `gorm:"type:varchar(64);not null;default:''" json:"original_username"`
+}
+
+// MentionInfo @提及显示信息（前端渲染用）
+type MentionInfo struct {
+	UID  uint   `json:"uid"`
+	Name string `json:"name"` // 当前显示名
 }
 
 // UserSearchResult @搜索用户结果

internal/repository/comment_mention_repo.go

@@ -17,8 +17,9 @@ func (r *CommentRepo) FindMentionsByComment(commentID uint) ([]model.CommentMent
 	return list, err
 }
 
-// LoadMentionsForComments 批量加载多条评论的有效@提及映射（username -> uid）
+// LoadMentionsForComments 批量加载多条评论的有效@提及映射
-// 传入的 comments 会被原地修改，填充 Mentions 字段
+// key=创建时的原始@用户名, value={uid, 用户当前显示名}
+// 用户改名后：原始名匹配body中的旧@文本，显示名随users表更新
 func (r *CommentRepo) LoadMentionsForComments(comments []model.Comment) error {
 	if len(comments) == 0 {
 		return nil
@@ -29,15 +30,15 @@ func (r *CommentRepo) LoadMentionsForComments(comments []model.Comment) error {
 		commentIDs[i] = c.ID
 	}
 
-	// 查询 comment_mentions JOIN users，拿到 username 和 uid
 	type mentionRow struct {
 		CommentID        uint
 		UID              uint
-		Username  string
+		OriginalUsername string
+		CurrentName      string
 	}
 	var rows []mentionRow
 	err := r.db.Table("comment_mentions").
-		Select("comment_mentions.comment_id, comment_mentions.uid, users.username").
+		Select("comment_mentions.comment_id, comment_mentions.uid, comment_mentions.original_username, users.username AS current_name").
 		Joins("LEFT JOIN users ON users.id = comment_mentions.uid").
 		Where("comment_mentions.comment_id IN ?", commentIDs).
 		Find(&rows).Error
@@ -45,13 +46,16 @@ func (r *CommentRepo) LoadMentionsForComments(comments []model.Comment) error {
 		return err
 	}
 
-	// 按 comment_id 分组
+	// 按 comment_id 分组，key = original_username, value = MentionInfo
-	mentionMap := make(map[uint]map[string]uint)
+	mentionMap := make(map[uint]map[string]model.MentionInfo)
 	for _, row := range rows {
 		if mentionMap[row.CommentID] == nil {
-			mentionMap[row.CommentID] = make(map[string]uint)
+			mentionMap[row.CommentID] = make(map[string]model.MentionInfo)
+		}
+		mentionMap[row.CommentID][row.OriginalUsername] = model.MentionInfo{
+			UID:  row.UID,
+			Name: row.CurrentName,
 		}
-		mentionMap[row.CommentID][row.Username] = row.UID
 	}
 
 	for i := range comments {

internal/service/comment_service.go

@@ -224,6 +224,7 @@ func (s *CommentService) parseMentions(commentID uint, body string) {
 			_ = s.repo.CreateMention(&model.CommentMention{
 				CommentID:        commentID,
 				UID:              rows[0].UID,
+				OriginalUsername: username,
 			})
 		}
 	}

templates/MetaLab-2026/static/js/post-comments.js

@@ -14,17 +14,17 @@
     var currentPage = 1;
     var totalPages = 1;
 
-    // 渲染@提及：有效提及渲染为蓝色链接，无效提及保持纯文本
+    // 渲染@提及：有效提及渲染为蓝色链接（显示当前用户名），无效提及保持纯文本
+    // mentions: { original_username: {uid, name} } — name为当前显示名，用户改名后自动更新
     function renderMentions(body, mentions) {
         body = escapeHtml(body);
         if (!mentions || Object.keys(mentions).length === 0) {
-            // 无 mentions 数据时仍高亮@，但不加链接（降级处理）
             return body.replace(/@(\S{1,16})/g, '<span class="reply-to">@$1</span>');
         }
         return body.replace(/@(\S{1,16})/g, function(match, username) {
-            var uid = mentions[username];
+            var info = mentions[username];
-            if (uid) {
+            if (info && info.uid) {
-                return '<a class="mention-link" href="/space/' + uid + '">@' + escapeHtml(username) + '</a>';
+                return '<a class="mention-link" href="/space/' + info.uid + '">@' + escapeHtml(info.name) + '</a>';
             }
             return match;
         });