refactor: adjusted centering

packages/pinball_components/sandbox/lib/stories/chrome_dino/chrome_dino_game.dart

@@ -10,9 +10,7 @@ class ChromeDinoGame extends Forge2DGame {
   Future<void> onLoad() async {
     await super.onLoad();
 
-    final center = screenToWorld(camera.viewport.canvasSize! / 2);
+    camera.followVector2(Vector2.zero());
-    await add(
+    await add(ChromeDino());
-      ChromeDino()..initialPosition = center,
-    );
   }
 }