fix(notification): improve local notification reliability on iOS/Android\n\n- iOS: set UNUserNotificationCenter delegate and present [.banner,.sound,.badge]\n- Android: create channels on init; use exactAllowWhileIdle; add RECEIVE_BOOT_COMPLETED and SCHEDULE_EXACT_ALARM\n- Dart: ensure iOS present options enabled; fix title variable shadowing\n\nValidation: scripts/check.sh passed (format/analyze/tests)\nRisk: exact alarms require user to allow 'Alarms & reminders' on Android 12+\nRollback: revert manifest perms and switch schedule mode back to inexact

ios/Runner/AppDelegate.swift

@@ -1,5 +1,6 @@
 import Flutter
 import UIKit
+import UserNotifications
 
 @main
 @objc class AppDelegate: FlutterAppDelegate {
@@ -7,7 +8,17 @@ import UIKit
     _ application: UIApplication,
     didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
   ) -> Bool {
+    UNUserNotificationCenter.current().delegate = self
     GeneratedPluginRegistrant.register(with: self)
     return super.application(application, didFinishLaunchingWithOptions: launchOptions)
   }
+
+  // 앱이 포그라운드일 때도 배너/사운드/배지 표시
+  func userNotificationCenter(
+    _ center: UNUserNotificationCenter,
+    willPresent notification: UNNotification,
+    withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void
+  ) {
+    completionHandler([.banner, .sound, .badge])
+  }
 }