- Guarded all Notification API usage to avoid ReferenceError on iOS Safari.
- Set default permission to 'denied' when Notification is undefined.
- Added early return in notification flow when Notifications API is unavailable.
- Wrapped Notification.permission, requestPermission(), and new Notification(...) with typeof checks.
- Updated SecureNotificationManager and app.jsx to degrade gracefully.
- Verified build passes and chat loads correctly on iOS without notifications.