Notifications NOTIFICATIONS (LOCAL — no server needed): FRAMEWORK: UserNotifications — UNUserNotificationCenter.current() PERMISSION STATES (CRITICAL — must handle ALL four states): 1. NOT DETERMINED: Call .requestAuthorization(options: [.alert, .badge, .sound]). System shows dialog. 2. AUTHORIZED: Schedule notifications normally. 3. DENIED: App CANNOT re-request permission. Must redirect user to System Settings. 4. PROVISIONAL: Quiet notifications — treat as authorized. PERMISSION IS SYSTEM-CONTROLLED (CRITICAL): - Notification authorization is owned by the SYSTEM, not the app. - Once the us…