refactor: Update renderer mode enum and input key handling for improved clarity

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

packages/wolf_3d_flutter/lib/wolf_3d_input_flutter.dart

@@ -12,6 +12,43 @@ import 'package:wolf_3d_dart/wolf_3d_input.dart';
 
 /// Translates Flutter keyboard and mouse state into engine-friendly actions.
 class Wolf3dFlutterInput extends Wolf3dInput {
+  /// Keyboard shortcut used by the Flutter host to cycle renderer modes.
+  LogicalKeyboardKey rendererToggleKey = LogicalKeyboardKey.keyR;
+
+  /// Keyboard shortcut used by the Flutter host to cycle ASCII themes.
+  LogicalKeyboardKey asciiThemeCycleKey = LogicalKeyboardKey.keyT;
+
+  /// Keyboard shortcut used by the Flutter host to toggle the FPS counter.
+  LogicalKeyboardKey fpsToggleKey = LogicalKeyboardKey.backquote;
+
+  /// Human-friendly label for [rendererToggleKey] shown in on-screen hints.
+  String get rendererToggleKeyLabel => _formatShortcutLabel(rendererToggleKey);
+
+  /// Human-friendly label for [asciiThemeCycleKey] shown in on-screen hints.
+  String get asciiThemeCycleKeyLabel =>
+      _formatShortcutLabel(asciiThemeCycleKey);
+
+  /// Human-friendly label for [fpsToggleKey] shown in on-screen hints.
+  String get fpsToggleKeyLabel => _formatShortcutLabel(fpsToggleKey);
+
+  String _formatShortcutLabel(LogicalKeyboardKey key) {
+    if (key == LogicalKeyboardKey.space) {
+      return 'SPACE';
+    }
+    if (key == LogicalKeyboardKey.tab) {
+      return 'TAB';
+    }
+    final label = key.keyLabel;
+    if (label.isNotEmpty) {
+      return label.toUpperCase();
+    }
+    final debugName = key.debugName;
+    if (debugName == null || debugName.isEmpty) {
+      return 'KEY';
+    }
+    return debugName.replaceFirst('Logical Keyboard Key ', '').toUpperCase();
+  }
+
   /// Mapping from logical game actions to one or more keyboard bindings.
   ///
   /// Each action can be rebound by replacing the matching set. The defaults