Test Progressive Web App APIs including service workers, web app manifest, background sync, and badging.
Test push notifications online — check Notification API and Web Push support, request permission, and send test notifications.
Test service worker online — check Service Worker API support, registration status, and active worker lifecycle.
Test web app manifest: detect manifest link, parse properties, and check display mode.
Test the Background Sync API: check SyncManager support and sync registration.
Test the Periodic Background Sync API: check support and permission status.
Test the Badging API: set and clear app badge counts.