added button

public/sw.js

@@ -0,0 +1,31 @@
+const CACHE = 'gj-v1'
+
+self.addEventListener('install', (e) => {
+  e.waitUntil(
+    caches.open(CACHE).then((cache) =>
+      cache.addAll(['/', '/manifest.json', '/icon.svg'])
+    )
+  )
+  self.skipWaiting()
+})
+
+self.addEventListener('activate', (e) => {
+  e.waitUntil(
+    caches.keys().then((keys) =>
+      Promise.all(keys.filter((k) => k !== CACHE).map((k) => caches.delete(k)))
+    )
+  )
+  self.clients.claim()
+})
+
+self.addEventListener('fetch', (e) => {
+  // Only cache GET requests for same-origin non-API resources
+  if (
+    e.request.method !== 'GET' ||
+    e.request.url.includes('/api/')
+  ) return
+
+  e.respondWith(
+    caches.match(e.request).then((cached) => cached || fetch(e.request))
+  )
+})