feat: image variants per image

internal/infrastructure/persistence/repositories/imageVariantFileRepository.go

@@ -70,6 +70,26 @@ func (v *VariantFileRepository) Delete(id uint32) error {
 	return v.db.Delete(&entity.ImageVariantFile{}, id).Error
 }
 
+func (v *VariantFileRepository) TotalsBySource() (map[string]domain.VariantFileTotals, error) {
+	var rows []struct {
+		SourceName string
+		Files      int
+		Bytes      int64
+	}
+	err := v.db.Model(&entity.ImageVariantFile{}).
+		Select("source_name, COUNT(*) AS files, COALESCE(SUM(size), 0) AS bytes").
+		Group("source_name").
+		Scan(&rows).Error
+	if err != nil {
+		return nil, err
+	}
+	totals := make(map[string]domain.VariantFileTotals, len(rows))
+	for _, row := range rows {
+		totals[row.SourceName] = domain.VariantFileTotals{Files: row.Files, Bytes: row.Bytes}
+	}
+	return totals, nil
+}
+
 func (v *VariantFileRepository) Totals() (map[string]domain.VariantFileTotals, error) {
 	var rows []struct {
 		VariantName string