feat: Refactor renderer key event handling and disable FPS counter by default

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

packages/wolf_3d_renderer/lib/base_renderer.dart

@@ -10,9 +10,13 @@ abstract class BaseWolfRenderer extends StatefulWidget {
   /// Engine instance that owns world state and the shared framebuffer.
   final WolfEngine engine;
 
+  /// Optional key handler invoked by the focused renderer shell.
+  final void Function(KeyEvent event)? onKeyEvent;
+
   /// Creates a renderer bound to [engine].
   const BaseWolfRenderer({
     required this.engine,
+    this.onKeyEvent,
     super.key,
   });
 }
@@ -75,7 +79,9 @@ abstract class BaseWolfRendererState<T extends BaseWolfRenderer>
       body: KeyboardListener(
         focusNode: focusNode,
         autofocus: true,
-        onKeyEvent: (_) {},
+        onKeyEvent: (event) {
+          widget.onKeyEvent?.call(event);
+        },
         child: Center(
           child: buildViewport(context),
         ),