Refactor menu rendering and improve projection sampling

- Updated AsciiRasterizer to support game and episode selection menus with improved layout and cursor handling.
- Enhanced SixelRasterizer and SoftwareRasterizer to modularize menu drawing logic for game and episode selection.
- Introduced new methods for drawing menus and applying fade effects across rasterizers.
- Adjusted wall texture sampling in Rasterizer to anchor to projection height center for consistent rendering.
- Added tests for wall texture sampling behavior to ensure legacy compatibility and new functionality.
- Modified Flutter audio adapter to use nullable access for active game and adjusted game selection logic in the main class.
- Cleaned up input handling in Wolf3dFlutterInput by removing unused menu tap variables.

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

apps/wolf_3d_gui/lib/screens/game_screen.dart

@@ -51,28 +51,9 @@ class _GameScreenState extends State<GameScreen> {
       child: Scaffold(
         body: LayoutBuilder(
           builder: (context, constraints) {
-            final viewportRect = _menuViewportRect(
-              Size(constraints.maxWidth, constraints.maxHeight),
-            );
-
             return Listener(
               onPointerDown: (event) {
                 widget.wolf3d.input.onPointerDown(event);
-                if (_engine.difficulty == null &&
-                    viewportRect.width > 0 &&
-                    viewportRect.height > 0 &&
-                    viewportRect.contains(event.localPosition)) {
-                  final normalizedX =
-                      (event.localPosition.dx - viewportRect.left) /
-                      viewportRect.width;
-                  final normalizedY =
-                      (event.localPosition.dy - viewportRect.top) /
-                      viewportRect.height;
-                  widget.wolf3d.input.queueMenuTap(
-                    x: normalizedX,
-                    y: normalizedY,
-                  );
-                }
               },
               onPointerUp: widget.wolf3d.input.onPointerUp,
               onPointerMove: widget.wolf3d.input.onPointerMove,
@@ -148,32 +129,4 @@ class _GameScreenState extends State<GameScreen> {
       ),
     );
   }
-
-  Rect _menuViewportRect(Size availableSize) {
-    if (availableSize.width <= 0 || availableSize.height <= 0) {
-      return Rect.zero;
-    }
-
-    const double aspect = 4 / 3;
-    final double outerPadding = _useAsciiMode ? 0.0 : 16.0;
-    final double maxWidth = (availableSize.width - (outerPadding * 2)).clamp(
-      1.0,
-      double.infinity,
-    );
-    final double maxHeight = (availableSize.height - (outerPadding * 2)).clamp(
-      1.0,
-      double.infinity,
-    );
-
-    double viewportWidth = maxWidth;
-    double viewportHeight = viewportWidth / aspect;
-    if (viewportHeight > maxHeight) {
-      viewportHeight = maxHeight;
-      viewportWidth = viewportHeight * aspect;
-    }
-
-    final double left = (availableSize.width - viewportWidth) / 2;
-    final double top = (availableSize.height - viewportHeight) / 2;
-    return Rect.fromLTWH(left, top, viewportWidth, viewportHeight);
-  }
 }