fix: improve extension download reliability and Qobuz API integration

- Add dedicated long-timeout download client (24h) for extension file downloads,
  preventing timeouts on large lossless audio files
- Skip unnecessary SongLink Deezer prelookup when an extension download provider
  handles the track, reducing latency and avoiding spurious API failures
- Prefer native track ID over Spotify ID when a source/provider is set, ensuring
  extension providers receive their own IDs correctly
- Update Qobuz MusicDL API endpoint and switch payload URL to open.qobuz.com
- Extract buildQobuzMusicDLPayload helper and add test coverage

go_backend/extension_runtime.go

@@ -81,13 +81,14 @@ func SetExtensionTokens(extensionID string, accessToken, refreshToken string, ex
 }
 
 type ExtensionRuntime struct {
-	extensionID string
-	manifest    *ExtensionManifest
-	settings    map[string]interface{}
-	httpClient  *http.Client
-	cookieJar   http.CookieJar
-	dataDir     string
-	vm          *goja.Runtime
+	extensionID    string
+	manifest       *ExtensionManifest
+	settings       map[string]interface{}
+	httpClient     *http.Client
+	downloadClient *http.Client
+	cookieJar      http.CookieJar
+	dataDir        string
+	vm             *goja.Runtime
 
 	storageMu      sync.RWMutex
 	storageCache   map[string]interface{}
@@ -132,13 +133,20 @@ func NewExtensionRuntime(ext *LoadedExtension) *ExtensionRuntime {
 		storageFlushDelay: defaultStorageFlushDelay,
 	}
 
+	runtime.httpClient = newExtensionHTTPClient(ext, jar, 30*time.Second)
+	runtime.downloadClient = newExtensionHTTPClient(ext, jar, DownloadTimeout)
+
+	return runtime
+}
+
+func newExtensionHTTPClient(ext *LoadedExtension, jar http.CookieJar, timeout time.Duration) *http.Client {
 	// Extension sandbox enforces HTTPS-only domains. Do not apply global
 	// allow_http scheme downgrade here, because some extension APIs (e.g.
 	// spotify-web) will redirect http -> https and can end up in 301 loops.
 	// We still reuse sharedTransport so insecure TLS compatibility mode remains effective.
 	client := &http.Client{
 		Transport: sharedTransport,
-		Timeout:   30 * time.Second,
+		Timeout:   timeout,
 		Jar:       jar,
 	}
 	client.CheckRedirect = func(req *http.Request, via []*http.Request) error {
@@ -165,9 +173,7 @@ func NewExtensionRuntime(ext *LoadedExtension) *ExtensionRuntime {
 		}
 		return nil
 	}
-	runtime.httpClient = client
-
-	return runtime
+	return client
 }
 
 type RedirectBlockedError struct {

go_backend/extension_runtime_file.go

@@ -174,7 +174,12 @@ func (r *ExtensionRuntime) fileDownload(call goja.FunctionCall) goja.Value {
 		req.Header.Set("User-Agent", "SpotiFLAC-Extension/1.0")
 	}
 
-	resp, err := r.httpClient.Do(req)
+	client := r.downloadClient
+	if client == nil {
+		client = r.httpClient
+	}
+
+	resp, err := client.Do(req)
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,

go_backend/qobuz.go

@@ -49,9 +49,10 @@ const (
 	qobuzArtistGetBaseURL   = "https://www.qobuz.com/api.json/0.2/artist/get?artist_id="
 	qobuzPlaylistGetBaseURL = "https://www.qobuz.com/api.json/0.2/playlist/get?playlist_id="
 	qobuzStoreSearchBaseURL = "https://www.qobuz.com/us-en/search/tracks/"
+	qobuzTrackOpenBaseURL   = "https://open.qobuz.com/track/"
 	qobuzTrackPlayBaseURL   = "https://play.qobuz.com/track/"
 	qobuzStoreBaseURL       = "https://www.qobuz.com/us-en"
-	qobuzDownloadAPIURL     = "https://www.musicdl.me/api/qobuz/download"
+	qobuzDownloadAPIURL     = "https://dl.musicdl.me/qobuz/download"
 	qobuzDabMusicAPIURL     = "https://dabmusic.xyz/api/stream?trackId="
 	qobuzDeebAPIURL         = "https://dab.yeet.su/api/stream?trackId="
 	qobuzAfkarAPIURL        = "https://qbz.afkarxyz.qzz.io/api/track/"
@@ -1631,19 +1632,23 @@ func fetchQobuzURLWithRetry(provider qobuzAPIProvider, trackID int64, quality st
 	return fetchQobuzURLSingleAttempt(provider, trackID, quality, timeout, "")
 }
 
+func buildQobuzMusicDLPayload(trackID int64, quality string) ([]byte, error) {
+	requestQuality := mapQobuzQualityCodeToAPI(quality)
+	payload := map[string]any{
+		"quality":      requestQuality,
+		"upload_to_r2": false,
+		"url":          fmt.Sprintf("%s%d", qobuzTrackOpenBaseURL, trackID),
+	}
+	return json.Marshal(payload)
+}
+
 func fetchQobuzURLSingleAttempt(provider qobuzAPIProvider, trackID int64, quality string, timeout time.Duration, country string) (qobuzDownloadInfo, error) {
 	var lastErr error
 	retryDelay := qobuzRetryDelay
 	var payloadBytes []byte
 	if provider.Kind == qobuzAPIKindMusicDL {
-		requestQuality := mapQobuzQualityCodeToAPI(quality)
-		payload := map[string]any{
-			"quality":      requestQuality,
-			"upload_to_r2": false,
-			"url":          fmt.Sprintf("%s%d", qobuzTrackPlayBaseURL, trackID),
-		}
 		var err error
-		payloadBytes, err = json.Marshal(payload)
+		payloadBytes, err = buildQobuzMusicDLPayload(trackID, quality)
 		if err != nil {
 			return qobuzDownloadInfo{}, fmt.Errorf("failed to encode qobuz request: %w", err)
 		}
@@ -1688,7 +1693,6 @@ func fetchQobuzURLSingleAttempt(provider qobuzAPIProvider, trackID int64, qualit
 		}
 		if provider.Kind == qobuzAPIKindMusicDL {
 			req.Header.Set("Content-Type", "application/json")
-			req.Header.Set("X-Debug-Key", getQobuzDebugKey())
 		}
 
 		resp, err := DoRequestWithUserAgent(client, req)

go_backend/qobuz_test.go

@@ -1,6 +1,9 @@
 package gobackend
 
-import "testing"
+import (
+	"encoding/json"
+	"testing"
+)
 
 func TestParseQobuzURL(t *testing.T) {
 	tests := []struct {
@@ -195,6 +198,28 @@ func TestGetQobuzDebugKey(t *testing.T) {
 	}
 }
 
+func TestBuildQobuzMusicDLPayloadUsesOpenTrackURL(t *testing.T) {
+	payloadBytes, err := buildQobuzMusicDLPayload(374610875, "7")
+	if err != nil {
+		t.Fatalf("buildQobuzMusicDLPayload returned error: %v", err)
+	}
+
+	var payload map[string]any
+	if err := json.Unmarshal(payloadBytes, &payload); err != nil {
+		t.Fatalf("payload is not valid JSON: %v", err)
+	}
+
+	if got := payload["url"]; got != "https://open.qobuz.com/track/374610875" {
+		t.Fatalf("payload url = %v, want open.qobuz.com track URL", got)
+	}
+	if got := payload["quality"]; got != "hi-res" {
+		t.Fatalf("payload quality = %v, want hi-res", got)
+	}
+	if got := payload["upload_to_r2"]; got != false {
+		t.Fatalf("payload upload_to_r2 = %v, want false", got)
+	}
+}
+
 func TestExtractQobuzAlbumIDsFromArtistHTML(t *testing.T) {
 	body := []byte(`
 		<button data-itemtype="album" data-itemId="0886446451985"></button>

lib/providers/download_queue_provider.dart

@@ -3594,6 +3594,15 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
       String? genre;
       String? label;
       String? copyright;
+      final extensionState = ref.read(extensionProvider);
+      final selectedExtensionDownloadProvider =
+          settings.useExtensionProviders &&
+          extensionState.extensions.any(
+            (e) =>
+                e.enabled &&
+                e.hasDownloadProvider &&
+                e.id.toLowerCase() == item.service.toLowerCase(),
+          );
 
       String? deezerTrackId = trackToDownload.deezerId;
       if (deezerTrackId == null && trackToDownload.id.startsWith('deezer:')) {
@@ -3628,7 +3637,8 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
       }
 
       // Fallback: Use SongLink to convert Spotify ID to Deezer ID
-      if (deezerTrackId == null &&
+      if (!selectedExtensionDownloadProvider &&
+          deezerTrackId == null &&
           trackToDownload.id.isNotEmpty &&
           !trackToDownload.id.startsWith('deezer:') &&
           !trackToDownload.id.startsWith('extension:')) {
@@ -3729,6 +3739,10 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
         if (shouldAbortWork('during SongLink availability lookup')) {
           return;
         }
+      } else if (selectedExtensionDownloadProvider && deezerTrackId == null) {
+        _log.d(
+          'Skipping Flutter SongLink Deezer prelookup for extension provider: ${item.service}',
+        );
       }
 
       if (deezerTrackId != null && deezerTrackId.isNotEmpty) {
@@ -3756,7 +3770,6 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
 
       Map<String, dynamic> result;
 
-      final extensionState = ref.read(extensionProvider);
       final hasActiveExtensions = extensionState.extensions.any(
         (e) => e.enabled,
       );

lib/providers/track_provider.dart

@@ -958,9 +958,16 @@ class TrackNotifier extends Notifier<TrackState> {
     final durationMs = _extractDurationMs(data);
 
     final itemType = data['item_type']?.toString();
+    final effectiveSource =
+        source ?? data['source']?.toString() ?? data['provider_id']?.toString();
+    final spotifyId = (data['spotify_id'] ?? '').toString();
+    final nativeId = (data['id'] ?? '').toString();
+    final preferredId = effectiveSource != null && effectiveSource.isNotEmpty
+        ? (nativeId.isNotEmpty ? nativeId : spotifyId)
+        : (spotifyId.isNotEmpty ? spotifyId : nativeId);
 
     return Track(
-      id: (data['spotify_id'] ?? data['id'] ?? '').toString(),
+      id: preferredId,
       name: (data['name'] ?? '').toString(),
       artistName: (data['artists'] ?? data['artist'] ?? '').toString(),
       albumName: (data['album_name'] ?? data['album'] ?? '').toString(),
@@ -974,10 +981,7 @@ class TrackNotifier extends Notifier<TrackState> {
       discNumber: data['disc_number'] as int?,
       releaseDate: data['release_date']?.toString(),
       totalTracks: data['total_tracks'] as int?,
-      source:
-          source ??
-          data['source']?.toString() ??
-          data['provider_id']?.toString(),
+      source: effectiveSource,
       albumType: data['album_type']?.toString(),
       itemType: itemType,
     );