feat: improve Extension Store with custom icons and various fixes

- Support custom extension icons from registry (iconUrl field)
- Support both camelCase and snake_case in registry JSON
- Fix download file extension (.spotiflac-ext)
- New extensions start disabled by default
- Preserve enabled state on extension upgrade
- Add toggle to show/hide Store tab in Settings > Options
- Reorder tabs: Home, History, Store, Settings

lib/models/settings.dart

@@ -28,6 +28,7 @@ class AppSettings {
   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
+  final bool showExtensionStore; // Show Extension Store tab in navigation
 
   const AppSettings({
     this.defaultService = 'tidal',
@@ -54,6 +55,7 @@ class AppSettings {
     this.useExtensionProviders = true, // Default: use extensions when available
     this.searchProvider, // Default: null (use Deezer/Spotify)
     this.separateSingles = false, // Default: disabled
+    this.showExtensionStore = true, // Default: show store
   });
 
   AppSettings copyWith({
@@ -81,6 +83,7 @@ class AppSettings {
     bool? useExtensionProviders,
     String? searchProvider,
     bool? separateSingles,
+    bool? showExtensionStore,
   }) {
     return AppSettings(
       defaultService: defaultService ?? this.defaultService,
@@ -107,6 +110,7 @@ class AppSettings {
       useExtensionProviders: useExtensionProviders ?? this.useExtensionProviders,
       searchProvider: searchProvider ?? this.searchProvider,
       separateSingles: separateSingles ?? this.separateSingles,
+      showExtensionStore: showExtensionStore ?? this.showExtensionStore,
     );
   }
 

lib/models/settings.g.dart

@@ -32,6 +32,7 @@ AppSettings _$AppSettingsFromJson(Map<String, dynamic> json) => AppSettings(
   useExtensionProviders: json['useExtensionProviders'] as bool? ?? true,
   searchProvider: json['searchProvider'] as String?,
   separateSingles: json['separateSingles'] as bool? ?? false,
+  showExtensionStore: json['showExtensionStore'] as bool? ?? true,
 );
 
 Map<String, dynamic> _$AppSettingsToJson(AppSettings instance) =>
@@ -60,4 +61,5 @@ Map<String, dynamic> _$AppSettingsToJson(AppSettings instance) =>
       'useExtensionProviders': instance.useExtensionProviders,
       'searchProvider': instance.searchProvider,
       'separateSingles': instance.separateSingles,
+      'showExtensionStore': instance.showExtensionStore,
     };