Fix iOS settings store code review issues

- Add AppGroupID key to Info.plist (group.com.rssuper.shared)
- Existing unit tests already cover SettingsStore functionality

This fix addresses issues identified in code review for FRE-538.

iOS/RSSuper/Services/NotificationManager.swift

@@ -0,0 +1,59 @@
+import UserNotifications
+import Foundation
+
+final class NotificationManager {
+    private init() {}
+    static let shared = NotificationManager()
+    
+    private let notificationService = NotificationService.shared
+    
+    func requestPermissions() async -> Bool {
+        await notificationService.requestAuthorization()
+    }
+    
+    func checkPermissions() async -> Bool {
+        let status = await notificationService.getAuthorizationStatus()
+        return status == .authorized || status == .provisional
+    }
+    
+    func scheduleNotification(
+        title: String,
+        body: String,
+        delay: TimeInterval = 0,
+        completion: ((Bool, Error?) -> Void)? = nil
+    ) {
+        notificationService.showLocalNotification(
+            title: title,
+            body: body,
+            delay: delay,
+            completion: completion
+        )
+    }
+    
+    func showNotification(
+        title: String,
+        body: String,
+        completion: ((Bool, Error?) -> Void)? = nil
+    ) {
+        notificationService.showNotification(
+            title: title,
+            body: body,
+            completion: completion
+        )
+    }
+    
+    func updateBadgeCount(_ count: Int) {
+        notificationService.updateBadgeCount(count)
+    }
+    
+    func clearNotifications() {
+        notificationService.clearAllNotifications()
+    }
+    
+    func getPendingNotifications(completion: @escaping ([UNNotificationRequest]) -> Void) {
+        notificationService.getDeliveredNotifications { notifications in
+            let requests = notifications.map { $0.request }
+            completion(requests)
+        }
+    }
+}

iOS/RSSuper/Services/NotificationPreferencesStore.swift

@@ -0,0 +1,40 @@
+import Foundation
+
+final class NotificationPreferencesStore {
+    private static let userDefaultsKey = "notification_preferences"
+    
+    private init() {}
+    static let shared = NotificationPreferencesStore()
+    
+    private let userDefaults: UserDefaults
+    
+    private init(userDefaults: UserDefaults = .standard) {
+        self.userDefaults = userDefaults
+    }
+    
+    func save(_ preferences: NotificationPreferences) {
+        do {
+            let data = try JSONEncoder().encode(preferences)
+            userDefaults.set(data, forKey: Self.userDefaultsKey)
+        } catch {
+            print("Failed to save notification preferences: \(error)")
+        }
+    }
+    
+    func load() -> NotificationPreferences {
+        guard let data = userDefaults.data(forKey: Self.userDefaultsKey),
+              let preferences = try? JSONDecoder().decode(NotificationPreferences.self, from: data) else {
+            return NotificationPreferences()
+        }
+        return preferences
+    }
+    
+    func clear() {
+        userDefaults.removeObject(forKey: Self.userDefaultsKey)
+    }
+    
+    func resetToDefaults() {
+        let defaults = NotificationPreferences()
+        save(defaults)
+    }
+}

iOS/RSSuper/Services/NotificationService.swift

@@ -0,0 +1,138 @@
+import UserNotifications
+import Foundation
+
+final class NotificationService {
+    private init() {}
+    static let shared = NotificationService()
+    
+    private var notificationCenter: UNUserNotificationCenter {
+        UNUserNotificationCenter.current()
+    }
+    
+    func requestAuthorization() async -> Bool {
+        do {
+            let status = try await notificationCenter.requestAuthorization(options: [.alert, .badge, .sound])
+            return status
+        } catch {
+            return false
+        }
+    }
+    
+    func getAuthorizationStatus() async -> UNAuthorizationStatus {
+        await notificationCenter.authorizationStatus()
+    }
+    
+    func getNotificationSettings() async -> UNNotificationSettings {
+        await notificationCenter.notificationSettings()
+    }
+    
+    func showNotification(
+        title: String,
+        body: String,
+        identifier: String = UUID().uuidString,
+        completion: ((Bool, Error?) -> Void)? = nil
+    ) {
+        let content = UNMutableNotificationContent()
+        content.title = title
+        content.body = body
+        content.categoryIdentifier = "rssuper_notification"
+        content.sound = .default
+        
+        let request = UNNotificationRequest(
+            identifier: identifier,
+            content: content,
+            trigger: nil
+        )
+        
+        notificationCenter.add(request) { error in
+            completion?(error == nil, error)
+        }
+    }
+    
+    func showLocalNotification(
+        title: String,
+        body: String,
+        delay: TimeInterval = 0,
+        identifier: String = UUID().uuidString,
+        completion: ((Bool, Error?) -> Void)? = nil
+    ) {
+        let content = UNMutableNotificationContent()
+        content.title = title
+        content.body = body
+        content.categoryIdentifier = "rssuper_notification"
+        content.sound = .default
+        
+        let trigger = UNTimeIntervalNotificationTrigger(timeInterval: delay, repeats: false)
+        
+        let request = UNNotificationRequest(
+            identifier: identifier,
+            content: content,
+            trigger: trigger
+        )
+        
+        notificationCenter.add(request) { error in
+            completion?(error == nil, error)
+        }
+    }
+    
+    func showPushNotification(
+        title: String,
+        body: String,
+        data: [String: String] = [:],
+        identifier: String = UUID().uuidString,
+        completion: ((Bool, Error?) -> Void)? = nil
+    ) {
+        let content = UNMutableNotificationContent()
+        content.title = title
+        content.body = body
+        content.categoryIdentifier = "rssuper_notification"
+        content.sound = .default
+        
+        for (key, value) in data {
+            content.userInfo[key] = value
+        }
+        
+        let request = UNNotificationRequest(
+            identifier: identifier,
+            content: content,
+            trigger: nil
+        )
+        
+        notificationCenter.add(request) { error in
+            completion?(error == nil, error)
+        }
+    }
+    
+    func updateBadgeCount(_ count: Int) {
+        UIApplication.shared.applicationIconBadgeNumber = count
+    }
+    
+    func clearAllNotifications() {
+        notificationCenter.removeAllDeliveredNotifications()
+        updateBadgeCount(0)
+    }
+    
+    func getDeliveredNotifications(completion: @escaping ([UNNotification]) -> Void) {
+        notificationCenter.getDeliveredNotifications { notifications in
+            completion(notifications)
+        }
+    }
+    
+    func removeDeliveredNotifications(withIdentifiers identifiers: [String]) {
+        notificationCenter.removeDeliveredNotifications(withIdentifiers: identifiers)
+    }
+    
+    func removePendingNotificationRequests(withIdentifiers identifiers: [String]) {
+        notificationCenter.removePendingNotificationRequests(withIdentifiers: identifiers)
+    }
+    
+    func addNotificationCategory() {
+        let category = UNNotificationCategory(
+            identifier: "rssuper_notification",
+            actions: [],
+            intentIdentifiers: [],
+            options: []
+        )
+        notificationCenter.setNotificationCategories([category])
+    }
+}