refactor: consolidate download domain into download package

internal/download/skip.go

@@ -0,0 +1,36 @@
+package download
+
+import (
+	"context"
+
+	"github.com/mathismqn/godeez/internal/fsutil"
+)
+
+func (d *Downloader) shouldSkipDownload(ctx context.Context, trackID, mediaFormat string) (string, bool) {
+	existing, err := d.store.DownloadInfo(trackID)
+	if err != nil || existing.Quality != mediaFormat {
+		return "", false
+	}
+
+	if fsutil.Exists(existing.Path) {
+		return existing.Path, true
+	}
+
+	if existing.Hash == "" {
+		return "", false
+	}
+
+	if err := d.initHashIndex(ctx); err != nil {
+		return "", false
+	}
+
+	foundPath, ok := d.hashIndex.find(existing.Hash)
+	if !ok {
+		return "", false
+	}
+
+	existing.Path = foundPath
+	_ = d.store.PutDownloadInfo(existing)
+
+	return foundPath, true
+}