feat: add PWA manifest and service worker routes with coverage

src/app.js

@@ -20,6 +20,14 @@ function html(status, markup) {
   };
 }
 
+function text(status, body, contentType) {
+  return {
+    status,
+    headers: { "content-type": contentType || "text/plain; charset=utf-8" },
+    body,
+  };
+}
+
 function parseJSON(rawBody) {
   if (!rawBody) {
     return {};
@@ -112,6 +120,30 @@ function buildApp({ config }) {
       return json(200, { ok: true });
     }
 
+    if (method === "GET" && path === "/manifest.webmanifest") {
+      return text(
+        200,
+        JSON.stringify({
+          name: "X Article to Audio",
+          short_name: "XArtAudio",
+          start_url: "/",
+          display: "standalone",
+          background_color: "#1d232a",
+          theme_color: "#1d232a",
+          icons: [],
+        }),
+        "application/manifest+json; charset=utf-8",
+      );
+    }
+
+    if (method === "GET" && path === "/sw.js") {
+      return text(
+        200,
+        "self.addEventListener('install', () => self.skipWaiting()); self.addEventListener('activate', () => self.clients.claim());",
+        "application/javascript; charset=utf-8",
+      );
+    }
+
     if (method === "GET" && path === "/") {
       return html(200, renderHomePage({
         authenticated: Boolean(userId),