feat: turn into a pwa

app/static/sw.js

@@ -0,0 +1,27 @@
+const CACHE = 'apoena-v1';
+const PRECACHE = ['/', '/worker.js', '/manifest.json', '/icon.svg', '/icon-maskable.svg'];
+
+self.addEventListener('install', e => {
+  e.waitUntil(caches.open(CACHE).then(c => c.addAll(PRECACHE)));
+  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 => {
+  const url = new URL(e.request.url);
+
+  // Pass through API calls
+  if (url.pathname === '/extract-audio') return;
+
+  e.respondWith(
+    caches.match(e.request).then(cached => cached || fetch(e.request))
+  );
+});