whole app

sw.js

@@ -0,0 +1,48 @@
+const CACHE_NAME = 'credittracker-v2';
+const ASSETS = [
+  './index.html',
+  './manifest.json',
+  './icon.svg',
+  './icon-maskable.svg'
+];
+
+// Install: pre-cache all app shell files
+self.addEventListener('install', event => {
+  event.waitUntil(
+    caches.open(CACHE_NAME).then(cache => cache.addAll(ASSETS))
+  );
+  self.skipWaiting();
+});
+
+// Activate: clean up old caches
+self.addEventListener('activate', event => {
+  event.waitUntil(
+    caches.keys().then(keys =>
+      Promise.all(keys.filter(k => k !== CACHE_NAME).map(k => caches.delete(k)))
+    )
+  );
+  self.clients.claim();
+});
+
+// Fetch: cache-first for app files, network-first for everything else
+self.addEventListener('fetch', event => {
+  // Only handle same-origin GET requests
+  if (event.request.method !== 'GET') return;
+
+  event.respondWith(
+    caches.match(event.request).then(cached => {
+      if (cached) return cached;
+      return fetch(event.request).then(response => {
+        // Cache successful responses for app assets
+        if (response.ok) {
+          const clone = response.clone();
+          caches.open(CACHE_NAME).then(cache => cache.put(event.request, clone));
+        }
+        return response;
+      });
+    }).catch(() => {
+      // Offline fallback: return the app shell
+      return caches.match('./index.html');
+    })
+  );
+});