feat: image variants per image

internal/infrastructure/useCases/ServeVariant.go

@@ -5,6 +5,7 @@ import (
 	"bytes"
 	"context"
 	"errors"
+	"fmt"
 	"io"
 	"path"
 	"slices"
@@ -263,7 +264,7 @@ func (u *ServeVariantUseCase) render(ctx context.Context, settings image.Variant
 func (u *ServeVariantUseCase) checkDeclaredPixels(data []byte) error {
 	width, height, err := u.renderer.DeclaredSize(bytes.NewReader(data))
 	if err != nil {
-		return err
+		return fmt.Errorf("%w: %v", image.ErrVariantSourceUnreadable, err)
 	}
 	if int64(width)*int64(height) > u.maxSourcePixels {
 		return image.ErrSourceTooLarge