切换批次和文件的 ID 类型为 UUID，更新相关逻辑和文档

internal/service/batch_service.go

@@ -57,9 +57,9 @@ func (s *BatchService) MarkAsExpired(batch *model.FileBatch) error {
 	return s.db.Model(batch).Update("status", "expired").Error
 }
 
-func (s *BatchService) DeleteBatch(ctx context.Context, batchID uint) error {
+func (s *BatchService) DeleteBatch(ctx context.Context, batchID string) error {
 	var batch model.FileBatch
-	if err := s.db.Preload("FileItems").First(&batch, batchID).Error; err != nil {
+	if err := s.db.Preload("FileItems").First(&batch, "id = ?", batchID).Error; err != nil {
 		return err
 	}
 
@@ -80,7 +80,7 @@ func (s *BatchService) DeleteBatch(ctx context.Context, batchID uint) error {
 	})
 }
 
-func (s *BatchService) IncrementDownloadCount(batchID uint) error {
+func (s *BatchService) IncrementDownloadCount(batchID string) error {
 	return s.db.Model(&model.FileBatch{}).Where("id = ?", batchID).
 		UpdateColumn("download_count", gorm.Expr("download_count + ?", 1)).Error
 }