feat: Add tests for Wolf3dGuiApp and refactor game data picker management

- Introduced unit tests for the Wolf3dGuiApp to ensure proper directory configuration and audio management.
- Refactored the GameDataPickerManager to streamline directory and file selection processes.
- Removed obsolete GameDataPickerManager and Wolf3dAppManager classes to simplify the architecture.
- Enhanced the Wolf3dFlutterEngine to improve game version handling during save loading.
- Updated existing tests to reflect changes in the game data management structure.
- Removed unnecessary dependencies and cleaned up the codebase for better maintainability.

Signed-off-by: Hans Kokx <hans.d.kokx@gmail.com>

packages/wolf_3d_flutter/lib/wolf_3d_flutter.dart

@@ -2,7 +2,6 @@
 library;
 
 import 'package:flutter/foundation.dart';
-import 'package:flutter/services.dart';
 import 'package:wolf_3d_dart/wolf_3d_data.dart';
 import 'package:wolf_3d_dart/wolf_3d_data_types.dart';
 import 'package:wolf_3d_dart/wolf_3d_engine.dart';
@@ -18,7 +17,6 @@ export 'audio/wolf3d_platform_audio.dart' show Wolf3dPlatformAudio;
 export 'managers/game_app_lifecycle_manager.dart' show GameAppLifecycleManager;
 export 'managers/game_data_directory_persistence.dart'
     show DefaultGameDataDirectoryPersistence;
-export 'managers/game_data_picker_manager.dart' show GameDataPickerManager;
 export 'managers/game_display_manager.dart' show GameDisplayManager;
 export 'managers/game_persistence_manager.dart' show GamePersistenceManager;
 export 'managers/game_renderer_mode_manager.dart'
@@ -31,22 +29,19 @@ export 'managers/game_screen_input_manager.dart'
         HostShortcutRegistry,
         GameScreenInputManager,
         isAltEnterShortcut;
-export 'managers/wolf3d_app_manager.dart' show Wolf3dAppManager;
 export 'screens/audio_gallery.dart' show AudioGallery;
 export 'screens/debug_tools_screen.dart' show DebugToolsScreen;
 export 'screens/game_screen.dart' show GameScreen;
-export 'screens/no_game_data_screen.dart' show NoGameDataScreen;
 export 'screens/sprite_gallery.dart' show SpriteGallery;
 export 'screens/vga_gallery.dart' show VgaGallery;
 export 'widgets/gallery_game_selector.dart'
     show GalleryGameSelector, formatGalleryGameTitle;
-export 'widgets/wolf3d_app.dart' show Wolf3dApp;
 export 'widgets/wolf_menu_shell.dart' show WolfMenuShell;
 
 /// Flutter-specific host facade built on top of [Wolf3dEngine].
 ///
 /// This type keeps platform-neutral session/engine state in the Dart package
-/// while owning Flutter-only concerns such as bundle loading and discovery.
+/// while owning Flutter-only concerns such as platform discovery helpers.
 class Wolf3dFlutterEngine extends Wolf3dEngine {
   /// Creates an empty facade that must be initialized with [init].
   Wolf3dFlutterEngine({
@@ -89,8 +84,9 @@ class Wolf3dFlutterEngine extends Wolf3dEngine {
   /// used when available. [additionalDirectories] are scanned after the
   /// primary directory and are not persisted.
   ///
-  /// This method merges bundled package data (when present) with discovered
-  /// external directories, deduplicating versions by [GameVersion].
+  /// This method scans only configured external directories, deduplicating
+  /// discovered versions by [GameVersion]. Shared package code does not bundle
+  /// or import game data on behalf of host applications.
   Future<Wolf3dFlutterEngine> init({
     String? directory,
     Iterable<String>? additionalDirectories,
@@ -110,35 +106,6 @@ class Wolf3dFlutterEngine extends Wolf3dEngine {
       await dataDirectoryPersistence.saveDataDirectory(requestedDirectory);
     }
 
-    // Bundled assets let the GUI work out of the box on supported platforms.
-    final versionsToTry = [
-      (version: GameVersion.retail, path: 'retail'),
-      (version: GameVersion.shareware, path: 'shareware'),
-    ];
-
-    for (final version in versionsToTry) {
-      try {
-        final ext = version.version.fileExtension;
-        final folder = 'packages/wolf_3d_assets/assets/${version.path}';
-
-        final data = WolfensteinLoader.loadFromBytes(
-          version: version.version,
-          vswap: await _tryLoad('$folder/VSWAP.$ext'),
-          mapHead: await _tryLoad('$folder/MAPHEAD.$ext'),
-          gameMaps: await _tryLoad('$folder/GAMEMAPS.$ext'),
-          vgaDict: await _tryLoad('$folder/VGADICT.$ext'),
-          vgaHead: await _tryLoad('$folder/VGAHEAD.$ext'),
-          vgaGraph: await _tryLoad('$folder/VGAGRAPH.$ext'),
-          audioHed: await _tryLoad('$folder/AUDIOHED.$ext'),
-          audioT: await _tryLoad('$folder/AUDIOT.$ext'),
-        );
-
-        availableGames.add(data);
-      } catch (e) {
-        debugPrint(e.toString());
-      }
-    }
-
     // On non-web platforms, also scan local filesystem locations for
     // user-supplied data folders so the host can pick up extra versions.
     final Set<String> directoriesToScan = <String>{};
@@ -175,14 +142,4 @@ class Wolf3dFlutterEngine extends Wolf3dEngine {
 
     return this;
   }
-
-  /// Loads an asset from the Flutter bundle, returning `null` when absent.
-  Future<ByteData?> _tryLoad(String path) async {
-    try {
-      return await rootBundle.load(path);
-    } catch (e) {
-      debugPrint("Asset not found: $path");
-      return null;
-    }
-  }
 }