upgrade to installable PWA. Fixes #6

index.html

@@ -9,6 +9,7 @@
     content="WijiBoard SCARA arm control dashboard. Web Bluetooth interface for the ESP32-C3 stepper controller." />
 
   <link rel="icon" type="image/svg+xml" href="favicon.svg" />
+  <link rel="manifest" href="manifest.json" />
 
   <!-- Shared styles -->
   <link rel="stylesheet" href="web/styles/base.css" />
@@ -181,6 +182,15 @@
     // ── Init router (last step) ────────────────────────────────────
     Router.init('#view', '#home');
 
+    // ── Register Service Worker for PWA ────────────────────────────
+    if ('serviceWorker' in navigator) {
+      window.addEventListener('load', () => {
+        navigator.serviceWorker.register('./sw.js').catch(err => {
+          console.warn('[PWA] Service Worker registration failed:', err);
+        });
+      });
+    }
+
     // ── Check Web Bluetooth availability ──────────────────────────
     if (!navigator.bluetooth) {
       setTimeout(() => {