fix(apps): 修复通知点击不显示ReminderOverlay和日历编辑后不刷新问题

- AppDelegate: 只存储payload字段而非整个userInfo字典
- LocalNotificationService: 移除旧的取消/稍后提醒action按钮配置
- ReminderNotificationCallbacks: 添加onNotificationPayloadReceived静态回调
- IOSNotificationPayloadBridge: 添加setPendingPayload方法
- main.dart: 设置onNotificationPayloadReceived触发ReminderOverlay显示，添加WidgetsBindingObserver处理后台恢复
- CalendarEventDetailScreen: 编辑保存后正确传递刷新信号给日视图

apps/ios/Runner/AppDelegate.swift

@@ -25,9 +25,8 @@ import UserNotifications
     withCompletionHandler completionHandler: @escaping () -> Void
   ) {
     let userInfo = response.notification.request.content.userInfo
-    if let jsonData = try? JSONSerialization.data(withJSONObject: userInfo, options: []),
-       let jsonString = String(data: jsonData, encoding: .utf8) {
-      UserDefaults.standard.set(jsonString, forKey: "pending_notification_payload")
+    if let payloadString = userInfo["payload"] as? String {
+      UserDefaults.standard.set(payloadString, forKey: "pending_notification_payload")
     }
     completionHandler()
   }