Fix iframe reload and service worker caching

src/service-worker.js

@@ -33,6 +33,7 @@ self.addEventListener('activate', (event) => {
 self.addEventListener('fetch', (event) => {
     // ignore POST requests etc
     if (event.request.method !== 'GET') return;
+    if (!event.request.url.startsWith('http')) return;
 
     async function respond() {
         const url = new URL(event.request.url);
@@ -49,7 +50,11 @@ self.addEventListener('fetch', (event) => {
             const response = await fetch(event.request);
 
             if (response.status === 200) {
-                cache.put(event.request, response.clone());
+                try {
+                    await cache.put(event.request, response.clone());
+                } catch (err) {
+                    console.warn('Service worker cache put skipped:', err);
+                }
             }
 
             return response;