feat: add external player mode for local library playback

lib/models/settings.dart

@@ -12,6 +12,7 @@ class AppSettings {
   final String downloadTreeUri; // SAF persistable tree URI
   final bool autoFallback;
   final bool autoSkipUnavailableTracks;
+  final String playerMode; // 'internal' or 'external'
   final bool smartQueueEnabled; // Enable smart curated autoplay queue
   final bool embedMetadata; // Master switch for metadata/cover/lyrics embedding
   final bool embedLyrics;
@@ -92,6 +93,7 @@ class AppSettings {
     this.downloadTreeUri = '',
     this.autoFallback = true,
     this.autoSkipUnavailableTracks = true,
+    this.playerMode = 'internal',
     this.smartQueueEnabled = true,
     this.embedMetadata = true,
     this.embedLyrics = true,
@@ -160,6 +162,7 @@ class AppSettings {
     String? downloadTreeUri,
     bool? autoFallback,
     bool? autoSkipUnavailableTracks,
+    String? playerMode,
     bool? smartQueueEnabled,
     bool? embedMetadata,
     bool? embedLyrics,
@@ -222,6 +225,7 @@ class AppSettings {
       autoFallback: autoFallback ?? this.autoFallback,
       autoSkipUnavailableTracks:
           autoSkipUnavailableTracks ?? this.autoSkipUnavailableTracks,
+      playerMode: playerMode ?? this.playerMode,
       smartQueueEnabled: smartQueueEnabled ?? this.smartQueueEnabled,
       embedMetadata: embedMetadata ?? this.embedMetadata,
       embedLyrics: embedLyrics ?? this.embedLyrics,

lib/models/settings.g.dart

@@ -15,6 +15,7 @@ AppSettings _$AppSettingsFromJson(Map<String, dynamic> json) => AppSettings(
   downloadTreeUri: json['downloadTreeUri'] as String? ?? '',
   autoFallback: json['autoFallback'] as bool? ?? true,
   autoSkipUnavailableTracks: json['autoSkipUnavailableTracks'] as bool? ?? true,
+  playerMode: json['playerMode'] as String? ?? 'internal',
   smartQueueEnabled: json['smartQueueEnabled'] as bool? ?? true,
   embedMetadata: json['embedMetadata'] as bool? ?? true,
   embedLyrics: json['embedLyrics'] as bool? ?? true,
@@ -93,6 +94,7 @@ Map<String, dynamic> _$AppSettingsToJson(
   'downloadTreeUri': instance.downloadTreeUri,
   'autoFallback': instance.autoFallback,
   'autoSkipUnavailableTracks': instance.autoSkipUnavailableTracks,
+  'playerMode': instance.playerMode,
   'smartQueueEnabled': instance.smartQueueEnabled,
   'embedMetadata': instance.embedMetadata,
   'embedLyrics': instance.embedLyrics,

lib/providers/playback_provider.dart

@@ -17,6 +17,7 @@ import 'package:spotiflac_android/services/ffmpeg_service.dart';
 import 'package:spotiflac_android/services/library_database.dart';
 import 'package:spotiflac_android/services/platform_bridge.dart';
 import 'package:spotiflac_android/utils/artist_utils.dart';
+import 'package:spotiflac_android/utils/file_access.dart';
 import 'package:spotiflac_android/utils/logger.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 
@@ -1647,6 +1648,16 @@ class PlaybackController extends Notifier<PlaybackState> {
         !_isPlayRequestCurrent(expectedRequestEpoch)) {
       return;
     }
+
+    final handledByExternal = await _tryPlayWithExternalPlayerIfConfigured(
+      uri: uri,
+      item: item,
+      expectedRequestEpoch: expectedRequestEpoch,
+    );
+    if (handledByExternal) {
+      return;
+    }
+
     final sourceUrl = uri.toString();
     await FFmpegService.activatePreparedNativeDashManifest(sourceUrl);
     if (!FFmpegService.isActiveLiveDecryptedUrl(sourceUrl)) {
@@ -1719,6 +1730,78 @@ class PlaybackController extends Notifier<PlaybackState> {
     }
   }
 
+  Future<bool> _tryPlayWithExternalPlayerIfConfigured({
+    required Uri uri,
+    required PlaybackItem item,
+    int? expectedRequestEpoch,
+  }) async {
+    final settings = ref.read(settingsProvider);
+    if (settings.playerMode != 'external') return false;
+    if (!item.isLocal) return false;
+
+    final externalPath = _externalPathFromPlaybackUri(uri);
+    if (externalPath == null || externalPath.isEmpty) return false;
+
+    _log.d('Opening with external player: $externalPath');
+    _updateMediaItemNotification(item);
+
+    try {
+      await openFile(externalPath);
+      if (expectedRequestEpoch != null &&
+          !_isPlayRequestCurrent(expectedRequestEpoch)) {
+        return true;
+      }
+      state = state.copyWith(
+        currentItem: item,
+        isLoading: false,
+        isBuffering: false,
+        isPlaying: false,
+        seekSupported: false,
+        position: Duration.zero,
+        bufferedPosition: Duration.zero,
+        duration: _fallbackDurationForItem(item),
+        clearError: true,
+      );
+      _syncServicePlaybackState(ProcessingState.idle, false);
+      unawaited(_savePlaybackSnapshot());
+      return true;
+    } catch (e) {
+      if (expectedRequestEpoch != null &&
+          !_isPlayRequestCurrent(expectedRequestEpoch)) {
+        return true;
+      }
+      _log.w('External player open failed: $e');
+      state = state.copyWith(
+        isLoading: false,
+        isBuffering: false,
+        isPlaying: false,
+      );
+      _setPlaybackError(
+        'Failed to open in external player: $e',
+        type: 'external_player_failed',
+      );
+      return true;
+    }
+  }
+
+  String? _externalPathFromPlaybackUri(Uri uri) {
+    if (uri.scheme == 'content') {
+      return uri.toString();
+    }
+    if (uri.scheme == 'file') {
+      try {
+        return uri.toFilePath();
+      } catch (_) {
+        return uri.path.isNotEmpty ? uri.path : null;
+      }
+    }
+    if (!uri.hasScheme) {
+      final asString = uri.toString().trim();
+      return asString.isNotEmpty ? asString : null;
+    }
+    return null;
+  }
+
   // ─── Lyrics fetching + parsing ───────────────────────────────────────────
 
   Future<void> _fetchLyricsForItem(PlaybackItem item) async {

lib/providers/settings_provider.dart

@@ -284,6 +284,12 @@ class SettingsNotifier extends Notifier<AppSettings> {
     _saveSettings();
   }
 
+  void setPlayerMode(String mode) {
+    final normalized = mode == 'external' ? 'external' : 'internal';
+    state = state.copyWith(playerMode: normalized);
+    _saveSettings();
+  }
+
   void setSmartQueueEnabled(bool enabled) {
     state = state.copyWith(smartQueueEnabled: enabled);
     _saveSettings();

lib/screens/settings/options_settings_page.dart

@@ -167,6 +167,16 @@ class OptionsSettingsPage extends ConsumerWidget {
                         .read(settingsProvider.notifier)
                         .setAutoSkipUnavailableTracks(v),
                   ),
+                  SettingsItem(
+                    icon: Icons.headphones,
+                    title: 'Music Player',
+                    subtitle: _playerModeLabel(settings.playerMode),
+                    onTap: () => _showPlayerModePicker(
+                      context,
+                      ref,
+                      settings.playerMode,
+                    ),
+                  ),
                   SettingsSwitchItem(
                     icon: Icons.queue_music_rounded,
                     title: context.l10n.settingsSmartQueueTitle,
@@ -318,6 +328,74 @@ class OptionsSettingsPage extends ConsumerWidget {
     );
   }
 
+  String _playerModeLabel(String mode) {
+    if (mode == 'external') {
+      return 'External app (Poweramp, etc.)';
+    }
+    return 'Internal player';
+  }
+
+  void _showPlayerModePicker(
+    BuildContext context,
+    WidgetRef ref,
+    String currentMode,
+  ) {
+    showModalBottomSheet<void>(
+      context: context,
+      useRootNavigator: true,
+      shape: const RoundedRectangleBorder(
+        borderRadius: BorderRadius.vertical(top: Radius.circular(24)),
+      ),
+      builder: (sheetContext) {
+        final colorScheme = Theme.of(sheetContext).colorScheme;
+        return SafeArea(
+          child: Column(
+            mainAxisSize: MainAxisSize.min,
+            children: [
+              const SizedBox(height: 8),
+              Container(
+                width: 40,
+                height: 4,
+                decoration: BoxDecoration(
+                  color: colorScheme.outlineVariant,
+                  borderRadius: BorderRadius.circular(999),
+                ),
+              ),
+              const SizedBox(height: 12),
+              ListTile(
+                leading: const Icon(Icons.play_circle_outline),
+                title: const Text('Internal Player'),
+                subtitle: const Text('Use built-in app playback and queue'),
+                trailing: currentMode == 'internal'
+                    ? Icon(Icons.check, color: colorScheme.primary)
+                    : null,
+                onTap: () {
+                  ref.read(settingsProvider.notifier).setPlayerMode('internal');
+                  Navigator.pop(sheetContext);
+                },
+              ),
+              ListTile(
+                leading: const Icon(Icons.open_in_new),
+                title: const Text('External Player'),
+                subtitle: const Text(
+                  'Open songs with apps like Poweramp, Musicolet, etc.',
+                ),
+                trailing: currentMode == 'external'
+                    ? Icon(Icons.check, color: colorScheme.primary)
+                    : null,
+                onTap: () {
+                  ref.read(settingsProvider.notifier).setPlayerMode('external');
+                  Navigator.pop(sheetContext);
+                },
+              ),
+              const SizedBox(height: 8),
+            ],
+          ),
+        );
+      },
+    );
+  }
+
   void _showClearHistoryDialog(
     BuildContext context,
     WidgetRef ref,