feat: PWA support + mobile-responsive layout + QR code to open Atlas on phone

Made-with: Cursor

public/sw.js

@@ -0,0 +1,47 @@
+// VIBN Service Worker — enables PWA install + basic offline shell
+const CACHE = 'vibn-v1';
+
+// Cache the app shell on install
+self.addEventListener('install', (e) => {
+  e.waitUntil(
+    caches.open(CACHE).then(cache =>
+      cache.addAll(['/', '/manifest.json'])
+    )
+  );
+  self.skipWaiting();
+});
+
+self.addEventListener('activate', () => self.clients.claim());
+
+// Network-first for API calls, cache-first for static assets
+self.addEventListener('fetch', (e) => {
+  const { request } = e;
+  const url = new URL(request.url);
+
+  // Never cache API calls
+  if (url.pathname.startsWith('/api/')) return;
+
+  // Cache-first for static assets
+  if (
+    request.destination === 'image' ||
+    request.destination === 'font' ||
+    url.pathname.startsWith('/_next/static/')
+  ) {
+    e.respondWith(
+      caches.match(request).then(cached => {
+        if (cached) return cached;
+        return fetch(request).then(res => {
+          const clone = res.clone();
+          caches.open(CACHE).then(c => c.put(request, clone));
+          return res;
+        });
+      })
+    );
+    return;
+  }
+
+  // Network-first for everything else (HTML pages)
+  e.respondWith(
+    fetch(request).catch(() => caches.match(request))
+  );
+});