feat: add Separate Singles Folder option

- Add albumType field to Track model with isSingle getter
- Add separateSingles setting in AppSettings
- Modify _buildOutputDir() to organize into Albums/ and Singles/ folders
- Add UI toggle in download settings page
- Parse album_type/record_type from Spotify and Deezer APIs

When enabled, singles are saved to a separate 'Singles' folder

lib/models/settings.dart

@@ -27,6 +27,7 @@ class AppSettings {
   final bool enableLogging; // Enable detailed logging for debugging
   final bool useExtensionProviders; // Use extension providers for downloads when available
   final String? searchProvider; // null/empty = default (Deezer/Spotify), otherwise extension ID
+  final bool separateSingles; // Separate singles/EPs into their own folder
 
   const AppSettings({
     this.defaultService = 'tidal',
@@ -52,6 +53,7 @@ class AppSettings {
     this.enableLogging = false, // Default: disabled for performance
     this.useExtensionProviders = true, // Default: use extensions when available
     this.searchProvider, // Default: null (use Deezer/Spotify)
+    this.separateSingles = false, // Default: disabled
   });
 
   AppSettings copyWith({
@@ -78,6 +80,7 @@ class AppSettings {
     bool? enableLogging,
     bool? useExtensionProviders,
     String? searchProvider,
+    bool? separateSingles,
   }) {
     return AppSettings(
       defaultService: defaultService ?? this.defaultService,
@@ -103,6 +106,7 @@ class AppSettings {
       enableLogging: enableLogging ?? this.enableLogging,
       useExtensionProviders: useExtensionProviders ?? this.useExtensionProviders,
       searchProvider: searchProvider ?? this.searchProvider,
+      separateSingles: separateSingles ?? this.separateSingles,
     );
   }
 

lib/models/settings.g.dart

@@ -31,6 +31,7 @@ AppSettings _$AppSettingsFromJson(Map<String, dynamic> json) => AppSettings(
   enableLogging: json['enableLogging'] as bool? ?? false,
   useExtensionProviders: json['useExtensionProviders'] as bool? ?? true,
   searchProvider: json['searchProvider'] as String?,
+  separateSingles: json['separateSingles'] as bool? ?? false,
 );
 
 Map<String, dynamic> _$AppSettingsToJson(AppSettings instance) =>
@@ -58,4 +59,5 @@ Map<String, dynamic> _$AppSettingsToJson(AppSettings instance) =>
       'enableLogging': instance.enableLogging,
       'useExtensionProviders': instance.useExtensionProviders,
       'searchProvider': instance.searchProvider,
+      'separateSingles': instance.separateSingles,
     };

lib/models/track.dart

@@ -19,6 +19,7 @@ class Track {
   final String? deezerId;
   final ServiceAvailability? availability;
   final String? source; // Extension ID that provided this track (null for built-in sources)
+  final String? albumType; // album, single, ep, compilation (from metadata API)
 
   const Track({
     required this.id,
@@ -35,8 +36,12 @@ class Track {
     this.deezerId,
     this.availability,
     this.source,
+    this.albumType,
   });
 
+  /// Check if this track is a single (based on album_type metadata)
+  bool get isSingle => albumType == 'single' || albumType == 'ep';
+
   factory Track.fromJson(Map<String, dynamic> json) => _$TrackFromJson(json);
   Map<String, dynamic> toJson() => _$TrackToJson(this);
   

lib/models/track.g.dart

@@ -25,6 +25,7 @@ Track _$TrackFromJson(Map<String, dynamic> json) => Track(
           json['availability'] as Map<String, dynamic>,
         ),
   source: json['source'] as String?,
+  albumType: json['albumType'] as String?,
 );
 
 Map<String, dynamic> _$TrackToJson(Track instance) => <String, dynamic>{
@@ -42,6 +43,7 @@ Map<String, dynamic> _$TrackToJson(Track instance) => <String, dynamic>{
   'deezerId': instance.deezerId,
   'availability': instance.availability,
   'source': instance.source,
+  'albumType': instance.albumType,
 };
 
 ServiceAvailability _$ServiceAvailabilityFromJson(Map<String, dynamic> json) =>