fix: 实现空间 TotalReads 统计，修复 selectMention 闭包

- P0-2: posts/show.html selectMention 闭包 var→let 修复
- P0-3: GetUserStats 增加 SUM(views_count) 统计，替换硬编码 int64(0)
- 更新 Fix_List.md 标注 P0-1/2/3 已修复

internal/repository/post_repo.go

@@ -93,18 +93,19 @@ func (r *PostRepo) CountUserPosts(userID uint) (int64, error) {
 	return count, err
 }
 
-// GetUserStats 获取用户的文章统计数据（总获赞/总收藏）
-func (r *PostRepo) GetUserStats(userID uint) (likes, favorites int64, err error) {
+// GetUserStats 获取用户的文章统计数据（总获赞/总收藏/总阅读）
+func (r *PostRepo) GetUserStats(userID uint) (likes, favorites, reads int64, err error) {
 	type stats struct {
-		TotalLikes    int64
+		TotalLikes     int64
 		TotalFavorites int64
+		TotalReads     int64
 	}
 	var s stats
 	err = r.db.Model(&model.Post{}).
-		Select("COALESCE(SUM(likes_count), 0) AS total_likes, COALESCE(SUM(favorites_count), 0) AS total_favorites").
+		Select("COALESCE(SUM(likes_count), 0) AS total_likes, COALESCE(SUM(favorites_count), 0) AS total_favorites, COALESCE(SUM(views_count), 0) AS total_reads").
 		Where("user_id = ? AND status = ? AND deleted_at IS NULL", userID, model.PostStatusApproved).
 		Scan(&s).Error
-	return s.TotalLikes, s.TotalFavorites, err
+	return s.TotalLikes, s.TotalFavorites, s.TotalReads, err
 }
 
 // FindByUserIDAndStatus 分页查询某用户指定状态的帖子（空 status=全状态）