fix: make service worker more resilient to prevent freezing

The service worker was causing 503 errors and freezing requests because:
- Pre-caching was trying to cache non-existent files
- Fetch handler was too aggressive with interception
- Failed cache operations blocked all requests

Fixes:
- Made pre-caching optional (logs errors but doesn't fail)
- More lenient fetch handler (only caches successful responses)
- Proper error handling for cache operations
- Only intercepts GET requests
- Falls back to network if cache fails

apps/frontend/src/service-worker.js

@@ -11,11 +11,6 @@ const IMAGE_CACHE = `${CACHE_VERSION}-images`;
 
 // Static assets to cache on install
 const STATIC_ASSETS = [
-  '/',
-  '/index.html',
-  '/main.js',
-  '/runtime.js',
-  '/styles.css',
   '/offline.html'
 ];
 
@@ -27,6 +22,8 @@ self.addEventListener('install', (event) => {
       console.log('[Service Worker] Caching static assets');
       return cache.addAll(STATIC_ASSETS).catch((err) => {
         console.error('[Service Worker] Failed to cache static assets:', err);
+        // Don't fail installation if caching fails
+        return Promise.resolve();
       });
     }).then(() => {
       return self.skipWaiting();
@@ -137,10 +134,13 @@ self.addEventListener('fetch', (event) => {
   event.respondWith(
     fetch(request)
       .then((response) => {
-        const responseClone = response.clone();
-        caches.open(DYNAMIC_CACHE).then((cache) => {
-          cache.put(request, responseClone);
-        });
+        // Only cache successful responses
+        if (response.ok) {
+          const responseClone = response.clone();
+          caches.open(DYNAMIC_CACHE).then((cache) => {
+            cache.put(request, responseClone);
+          });
+        }
         return response;
       })
       .catch(() => {