feat(library): add quality label display modes

test/audio_quality_badge_policy_test.dart

@@ -1,4 +1,5 @@
 import 'package:flutter_test/flutter_test.dart';
+import 'package:spotiflac_android/models/settings.dart';
 import 'package:spotiflac_android/utils/audio_quality_badge_policy.dart';
 
 void main() {
@@ -22,4 +23,68 @@ void main() {
       expect(shouldHighlightAudioQualityBadge('16-bit/44.1kHz'), isFalse);
     });
   });
+
+  group('Library audio quality label mode', () {
+    test('uses measured bitrate by default', () {
+      expect(
+        buildLibraryAudioQualityLabel(
+          mode: AppSettings.libraryQualityLabelBitrate,
+          format: 'flac',
+          bitrateKbps: 1760,
+          bitDepth: 24,
+          sampleRate: 48000,
+        ),
+        'FLAC 1760kbps',
+      );
+      expect(
+        normalizeLibraryQualityLabelMode('unsupported'),
+        AppSettings.libraryQualityLabelBitrate,
+      );
+    });
+
+    test('restores legacy bit depth and sample rate labels', () {
+      expect(
+        buildLibraryAudioQualityLabel(
+          mode: AppSettings.libraryQualityLabelBitDepth,
+          format: 'flac',
+          bitrateKbps: 1760,
+          bitDepth: 24,
+          sampleRate: 48000,
+        ),
+        '24-bit/48kHz',
+      );
+    });
+
+    test('keeps bitrate meaningful for lossy formats', () {
+      expect(
+        buildLibraryAudioQualityLabel(
+          mode: AppSettings.libraryQualityLabelBitDepth,
+          format: 'mp3',
+          bitrateKbps: 320,
+          bitDepth: 16,
+          sampleRate: 44100,
+        ),
+        'MP3 320kbps',
+      );
+    });
+
+    test('falls back when the preferred metadata is unavailable', () {
+      expect(
+        buildLibraryAudioQualityLabel(
+          mode: AppSettings.libraryQualityLabelBitDepth,
+          format: 'flac',
+          bitrateKbps: 950,
+          storedQuality: 'LOSSLESS',
+        ),
+        'FLAC 950kbps',
+      );
+      expect(
+        buildLibraryAudioQualityLabel(
+          mode: AppSettings.libraryQualityLabelBitrate,
+          storedQuality: '24-bit/96kHz',
+        ),
+        '24-bit/96kHz',
+      );
+    });
+  });
 }

test/models_and_utils_test.dart

@@ -510,6 +510,10 @@ void main() {
       expect(settings.deduplicateDownloads, isTrue);
       expect(settings.allowQualityVariants, isFalse);
       expect(settings.nativeDownloadWorkerEnabled, isFalse);
+      expect(
+        settings.libraryQualityLabelMode,
+        AppSettings.libraryQualityLabelBitrate,
+      );
     });
 
     test('copyWith updates values and can clear nullable provider fields', () {
@@ -526,6 +530,7 @@ void main() {
         lyricsAppleElrcWordSync: true,
         deduplicateDownloads: false,
         allowQualityVariants: true,
+        libraryQualityLabelMode: AppSettings.libraryQualityLabelBitDepth,
         clearDownloadFallbackExtensionIds: true,
         clearSearchProvider: true,
         clearHomeFeedProvider: true,
@@ -537,6 +542,10 @@ void main() {
       expect(updated.lyricsAppleElrcWordSync, isTrue);
       expect(updated.deduplicateDownloads, isFalse);
       expect(updated.allowQualityVariants, isTrue);
+      expect(
+        updated.libraryQualityLabelMode,
+        AppSettings.libraryQualityLabelBitDepth,
+      );
       expect(updated.downloadFallbackExtensionIds, isNull);
       expect(updated.searchProvider, isNull);
       expect(updated.homeFeedProvider, isNull);
@@ -563,6 +572,7 @@ void main() {
         deduplicateDownloads: false,
         allowQualityVariants: true,
         nativeDownloadWorkerEnabled: true,
+        libraryQualityLabelMode: AppSettings.libraryQualityLabelBitDepth,
       );
 
       final decoded = AppSettings.fromJson(settings.toJson());
@@ -582,6 +592,10 @@ void main() {
       expect(decoded.musixmatchLanguage, 'id');
       expect(decoded.lyricsAppleElrcWordSync, isTrue);
       expect(decoded.lastSeenVersion, '4.5.0');
+      expect(
+        decoded.libraryQualityLabelMode,
+        AppSettings.libraryQualityLabelBitDepth,
+      );
       expect(decoded.deduplicateDownloads, isFalse);
       expect(decoded.allowQualityVariants, isTrue);
       expect(decoded.nativeDownloadWorkerEnabled, isTrue);