chore: add flutter_riverpod and wrap app in ProviderScope

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

lib/main.dart

@@ -1,5 +1,6 @@
 import 'dart:io';
 import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'pages/pokemon_detail.dart';
 import 'pages/main_page.dart';
 import 'package:google_fonts/google_fonts.dart';
@@ -12,7 +13,7 @@ void main() {
     sqfliteFfiInit();
     databaseFactory = databaseFactoryFfi;
   }
-  runApp(const MyApp());
+  runApp(const ProviderScope(child: MyApp()));
 }
 
 class MyApp extends StatelessWidget {