service-worker

Service Worker API implementation guide — registration, lifecycle management, caching strategies, push notifications, and background sync. Use when: (1) creating or modifying service worker files (sw.js), (2) implementing offline-first caching (cache-first, network-first, stale-while-revalidate), (3) setting up push notifications or background sync, (4) debugging service worker registration, scope, or update issues, (5) implementing navigation preload, (6) user mentions 'service worker', 'sw.js', 'offline support', 'cache strategy', 'push notification', 'background sync', 'workbox alternative', or 'PWA caching'.