feat: add complete Mayday iOS Xcode project

- Swift 6, SwiftUI, MVVM + async/await architecture
- iOS 17.0 minimum deployment target
- Two targets: Mayday app + MaydayLiveActivity widget extension
- Models: UserResponse, TokenPair, AppNotification, SessionResponse, AlertAttributes
- Services: HTTPClient (actor), AuthService, KeychainService, NotificationsAPIService, PushNotificationService
- ViewModels: AuthViewModel, NotificationsViewModel, SettingsViewModel
- Views: Login/Register/VerifyEmail, NotificationsList/Detail, Settings/ChangePassword/Sessions
- APNs push notifications with UIApplicationDelegate
- ActivityKit Live Activities for Dynamic Island + Lock Screen
- Keychain (Security framework) token storage
- 30-second polling with pagination for notifications
- Xcode project file (project.pbxproj) with correct build phases for both targets

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Mayday/Models/AppNotification.swift

@@ -0,0 +1,47 @@
+import Foundation
+
+struct AppNotification: Codable, Identifiable {
+    let id: UUID
+    let topic: String
+    let subject: String
+    let body: String
+    let metadata: [String: String]?
+    let status: NotificationStatus
+    let channel: NotificationChannel
+    let readAt: Date?
+    let createdAt: Date
+    let updatedAt: Date
+
+    enum CodingKeys: String, CodingKey {
+        case id, topic, subject, body, metadata, status, channel
+        case readAt = "read_at"
+        case createdAt = "created_at"
+        case updatedAt = "updated_at"
+    }
+
+    var isRead: Bool { readAt != nil }
+}
+
+enum NotificationStatus: String, Codable {
+    case sent
+    case delivered
+    case read
+}
+
+enum NotificationChannel: String, Codable {
+    case inApp = "in_app"
+    case push
+    case email
+}
+
+struct NotificationsPage: Codable {
+    let items: [AppNotification]
+    let total: Int
+    let page: Int
+    let perPage: Int
+
+    enum CodingKeys: String, CodingKey {
+        case items, total, page
+        case perPage = "per_page"
+    }
+}