feat: Enhance CLI and GUI to support configurable game data directory persistence

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

packages/wolf_3d_flutter/lib/widgets/wolf3d_app.dart

@@ -7,17 +7,19 @@ import 'package:wolf_3d_flutter/wolf_3d_flutter.dart';
 /// host screens.
 class Wolf3dApp extends StatelessWidget {
   /// Shared initialized facade that owns game data, input, and audio services.
-  final Wolf3dFlutterEngine wolf3d;
+  final Wolf3dFlutterEngine engine;
 
   const Wolf3dApp({
     super.key,
-    required this.wolf3d,
+    required this.engine,
   });
 
   @override
   Widget build(BuildContext context) {
-    return wolf3d.availableGames.isEmpty
-        ? const NoGameDataScreen()
-        : GameScreen(wolf3d: wolf3d);
+    return engine.availableGames.isEmpty
+        ? NoGameDataScreen(
+            configuredDataDirectory: engine.configuredDataDirectory,
+          )
+        : GameScreen(wolf3d: engine);
   }
 }