Wire season flow: map screen, progress save, win recording, next stage

SaveRepository (versioned JSON over prefs) with best-result merging and
unlock walking; ContentRepository loads the bundled pack; SeasonFlow/
Progress notifiers orchestrate stage start -> win record -> advance.
Season map grid with stars/locks, Home -> Map -> Game navigation,
close button, next-stage action on the win overlay.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

lib/main.dart

@@ -2,8 +2,16 @@ import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 
 import 'app.dart';
+import 'data/save_repository.dart';
+import 'state/providers.dart';
 
-void main() {
+Future<void> main() async {
   WidgetsFlutterBinding.ensureInitialized();
-  runApp(const ProviderScope(child: BlockSeasonsApp()));
+  final saveRepository = await SaveRepository.open();
+  runApp(
+    ProviderScope(
+      overrides: [saveRepositoryProvider.overrideWithValue(saveRepository)],
+      child: const BlockSeasonsApp(),
+    ),
+  );
 }