feat: add Offline Mode Indicator (Bunker Status)

public/sw.js

@@ -43,10 +43,19 @@ self.addEventListener('install', (event) => {
             });
             await Promise.all(promises);
             console.log('✅ PWA: Bunker build finished');
+
+            // Signal to clients that pre-caching is complete
+            broadcast({ type: 'PRECACHE_COMPLETE', version: CACHE_NAME });
         })
     );
 });
 
+// Helper: Broadcast to all clients
+async function broadcast(message) {
+    const clients = await self.clients.matchAll();
+    clients.forEach(client => client.postMessage(message));
+}
+
 // Activate: Alte Bunker räumen
 self.addEventListener('activate', (event) => {
     event.waitUntil(
@@ -64,6 +73,17 @@ self.addEventListener('activate', (event) => {
     self.clients.claim();
 });
 
+// Communication: Listen for status checks
+self.addEventListener('message', (event) => {
+    if (event.data?.type === 'CHECK_BUNKER_STATUS') {
+        event.source.postMessage({
+            type: 'BUNKER_STATUS',
+            isReady: true,
+            version: CACHE_NAME
+        });
+    }
+});
+
 self.addEventListener('fetch', (event) => {
     // Nur GET-Requests cachen
     if (event.request.method !== 'GET') return;