Add FLAC lyrics embedding with LRCLIB fallback (#151)

* Update lyrics code

* Refactor DownloadFile to use default HTTP client

backend/deezer.go

@@ -173,7 +173,13 @@ func (d *DeezerDownloader) GetDownloadURL(trackID int64) (string, error) {
 }
 
 func (d *DeezerDownloader) DownloadFile(url, filepath string) error {
-	resp, err := d.client.Get(url)
+	// Use a separate client with a longer timeout. The default client's 60s limit
+	// causes downloads to fail on slow connections or for large Hi-Res files.
+	downloadClient := &http.Client{
+		Timeout: 5 * time.Minute, // 5 minutes for large files
+	}
+
+	resp, err := downloadClient.Get(url)
 	if err != nil {
 		return fmt.Errorf("failed to download file: %w", err)
 	}