feat: improve PWA auth robustness and session management

src/components/PWARegistration.tsx

@@ -10,6 +10,21 @@ export default function PWARegistration() {
                     .register('/sw.js')
                     .then((registration) => {
                         console.log('SW registered: ', registration);
+
+                        // Check for updates
+                        registration.onupdatefound = () => {
+                            const installingWorker = registration.installing;
+                            if (installingWorker == null) return;
+                            installingWorker.onstatechange = () => {
+                                if (installingWorker.state === 'installed') {
+                                    if (navigator.serviceWorker.controller) {
+                                        console.log('[SW] New content is available; please refresh.');
+                                    } else {
+                                        console.log('[SW] Content is cached for offline use.');
+                                    }
+                                }
+                            };
+                        };
                     })
                     .catch((registrationError) => {
                         console.log('SW registration failed: ', registrationError);