Scaffold Block Seasons Flutter app

flutter create (com.airkjw.blockseasons, iOS+Android), Riverpod,
shared_preferences, audioplayers, gen-l10n EN/KO wiring, app shell
with Home -> Game placeholder.

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

ios/Runner/AppDelegate.swift

@@ -0,0 +1,13 @@
+import Flutter
+import UIKit
+
+@main
+@objc class AppDelegate: FlutterAppDelegate {
+  override func application(
+    _ application: UIApplication,
+    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
+  ) -> Bool {
+    GeneratedPluginRegistrant.register(with: self)
+    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
+  }
+}