feat: Add triggerQuitOnInitForTest to GameScreen for deterministic testing

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

apps/wolf_3d_gui/lib/screens/game_screen.dart

@@ -135,6 +135,10 @@ class GameScreen extends StatefulWidget {
   @visibleForTesting
   final bool skipEngineBootstrapForTest;
 
+  /// Triggers the quit flow during init for deterministic widget tests.
+  @visibleForTesting
+  final bool triggerQuitOnInitForTest;
+
   /// Creates a gameplay screen driven by [wolf3d].
   const GameScreen({
     required this.wolf3d,
@@ -142,6 +146,7 @@ class GameScreen extends StatefulWidget {
     this.hostShortcutRegistry = HostShortcutRegistry.defaults,
     this.appExitHandler,
     this.skipEngineBootstrapForTest = false,
+    this.triggerQuitOnInitForTest = false,
     super.key,
   });
 
@@ -164,6 +169,9 @@ class _GameScreenState extends State<GameScreen> {
   void initState() {
     super.initState();
     if (widget.skipEngineBootstrapForTest) {
+      if (widget.triggerQuitOnInitForTest) {
+        unawaited(_quitApplication());
+      }
       return;
     }
 
@@ -262,9 +270,6 @@ class _GameScreenState extends State<GameScreen> {
     await quit;
   }
 
-  @visibleForTesting
-  Future<void> debugQuitForTest() => _quitApplication();
-
   @override
   Widget build(BuildContext context) {
     final engine = _engine;