refactor: move user score to gameover dialog

lib/game/view/pinball_game_page.dart

@@ -70,7 +70,10 @@ class _PinballGameViewState extends State<PinballGameView> {
           showDialog<void>(
             context: context,
             builder: (_) {
-              return const GameOverDialog();
+              return GameOverDialog(
+                score: state.score,
+                theme: widget.theme.characterTheme,
+              );
             },
           );
         }

lib/game/view/widgets/game_over_dialog.dart

@@ -1,21 +1,38 @@
 import 'package:flutter/material.dart';
 import 'package:pinball/game/game.dart';
+import 'package:pinball_theme/pinball_theme.dart';
 
 /// {@template game_over_dialog}
 /// [Dialog] displayed when the [PinballGame] is over.
 /// {@endtemplate}
 class GameOverDialog extends StatelessWidget {
   /// {@macro game_over_dialog}
-  const GameOverDialog({Key? key}) : super(key: key);
+  const GameOverDialog({Key? key, required this.score, required this.theme})
+      : super(key: key);
+
+  final int score;
+  final CharacterTheme theme;
 
   @override
   Widget build(BuildContext context) {
-    return const Dialog(
+    return Dialog(
       child: SizedBox(
         width: 200,
         height: 200,
         child: Center(
-          child: Text('Game Over'),
+          child: Column(
+            mainAxisAlignment: MainAxisAlignment.center,
+            children: [
+              const Text('Game Over'),
+              Text('Congratulations! your score is $score'),
+              TextButton(
+                onPressed: () {
+                  //TODO: navigate to LeadersboardPage
+                },
+                child: const Text('Add User'),
+              ),
+            ],
+          ),
         ),
       ),
     );