feat(repository): enhance repository methods with batch processing and transaction support

- Updated Like and Unlike methods in CommentRepository to use transactions for data consistency.
- Introduced IsLikedBatch method for batch checking if comments are liked, addressing N+1 query issues.
- Enhanced BatchDelete method in PostRepository to perform batch deletions within a single transaction, improving efficiency.
- Added BatchUpdateStatus method for posts to utilize a single SQL update for status changes, reducing database load.
- Implemented BatchUpdateSortOrder in StickerRepository using CASE WHEN for efficient sorting updates.
- Added IsFollowingBatch and IsBlockedBatch methods in UserRepository for batch checking follow and block relationships, optimizing performance.

internal/repository/operation_log_repo.go

@@ -89,7 +89,7 @@ func (r *OperationLogRepository) DeleteOldLogs(ctx context.Context, beforeDate s
 	return r.db.WithContext(ctx).Where("created_at < ?", beforeDate).Delete(&model.OperationLog{}).Error
 }
 
-// GetStatistics 获取操作日志统计
+// GetStatistics 获取操作日志统计（使用单次 GROUP BY 查询，避免多次 COUNT)
 func (r *OperationLogRepository) GetStatistics(ctx context.Context, startTime, endTime string) (*OperationLogStatistics, error) {
 	stats := &OperationLogStatistics{}
 
@@ -101,16 +101,25 @@ func (r *OperationLogRepository) GetStatistics(ctx context.Context, startTime, e
 		query = query.Where("created_at <= ?", endTime)
 	}
 
-	if err := query.Count(&stats.TotalCount).Error; err != nil {
+	// 使用单次 GROUP BY 查询获取各状态计数
+	type statusCount struct {
+		Status string
+		Count  int64
+	}
+	var results []statusCount
+	err := query.Select("status, count(*) as count").Group("status").Scan(&results).Error
+	if err != nil {
 		return nil, err
 	}
 
-	if err := query.Where("status = ?", "success").Count(&stats.SuccessCount).Error; err != nil {
-		return nil, err
-	}
-
-	if err := query.Where("status = ?", "fail").Count(&stats.FailCount).Error; err != nil {
-		return nil, err
+	// 汇总结果
+	for _, r := range results {
+		stats.TotalCount += r.Count
+		if r.Status == "success" {
+			stats.SuccessCount = r.Count
+		} else if r.Status == "fail" {
+			stats.FailCount = r.Count
+		}
 	}
 
 	return stats, nil