Ensure offline users vibrate and auto-respond to manual pings

Three fixes for offline ping gaps:

1. SW silent push fallback: when a manual ping arrives as a silent push
   but no app window is open, show a visible notification with vibration
   instead of failing silently.

2. SW notificationclick: when opening a fresh window (app was closed),
   append ?ping=manual to the URL so the app can detect it was pinged.

3. page.tsx: on mount, detect ?ping=manual param, clean it from the URL,
   and auto-fire GPS once the WebSocket connection is established.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

public/sw.js

@@ -346,8 +346,24 @@ self.addEventListener('push', (event) => {
     const isManual = !!(data.data?.manual);
 
     event.waitUntil(
-      requestLocationFromClient(isManual).then((sent) => {
+      requestLocationFromClient(isManual).then(async (sent) => {
         console.log('[SW] Push location request sent:', sent, 'manual:', isManual);
+        // If no app window is open and this is a manual ping, show a visible notification
+        // so the user can tap to open the app and auto-respond with location
+        if (!sent && isManual) {
+          await self.registration.showNotification('📍 Someone is looking for you!', {
+            body: 'Tap to share your location',
+            icon: '/icon-192.png',
+            badge: '/icon-192.png',
+            tag: `callout-${data.data?.roomSlug || 'unknown'}`,
+            data: { type: 'callout', roomSlug: data.data?.roomSlug, manual: true },
+            vibrate: [200, 100, 200, 100, 400],
+            requireInteraction: true,
+            actions: [{ action: 'view', title: 'Open Map' }],
+            renotify: true,
+            silent: false,
+          });
+        }
       })
     );
     return;
@@ -418,7 +434,9 @@ self.addEventListener('notificationclick', (event) => {
         }
       }
       if (clients.openWindow) {
-        return clients.openWindow(targetUrl);
+        // If manual ping, append ?ping=manual so the app auto-responds with GPS on load
+        const openUrl = data.manual ? `${targetUrl}?ping=manual` : targetUrl;
+        return clients.openWindow(openUrl);
       }
     })
   );

src/app/[slug]/page.tsx

@@ -47,6 +47,23 @@ export default function RoomPage() {
   const [shouldAutoStartSharing, setShouldAutoStartSharing] = useState(false);
   const [zoomToLocation, setZoomToLocation] = useState<{ latitude: number; longitude: number } | null>(null);
   const [needsJoin, setNeedsJoin] = useState(false);
+  const [pendingManualPing, setPendingManualPing] = useState(false);
+
+  // Check if opened from a manual ping notification (e.g. ?ping=manual)
+  useEffect(() => {
+    if (typeof window !== 'undefined') {
+      const params = new URLSearchParams(window.location.search);
+      if (params.get('ping') === 'manual') {
+        // Clean the param from URL
+        params.delete('ping');
+        const newUrl = params.toString()
+          ? `${window.location.pathname}?${params.toString()}`
+          : window.location.pathname;
+        window.history.replaceState({}, '', newUrl);
+        setPendingManualPing(true);
+      }
+    }
+  }, []);
 
   // Load user and sharing preference from localStorage
   useEffect(() => {
@@ -207,6 +224,15 @@ export default function RoomPage() {
     }
   }, [isConnected, isPushSubscribed, subscribePush, syncUrl]);
 
+  // Execute pending manual ping once connected (from notification tap while app was closed)
+  useEffect(() => {
+    if (pendingManualPing && isConnected) {
+      console.log('Executing pending manual ping from notification tap');
+      setPendingManualPing(false);
+      handleManualPing();
+    }
+  }, [pendingManualPing, isConnected, handleManualPing]);
+
   // Restore last known location immediately when connected
   const hasRestoredLocationRef = useRef(false);
   useEffect(() => {