feat: Add Progressive Web App (PWA) support with service worker, manifest, and icons, including associated tests.

app/index.html

@@ -10,6 +10,13 @@
     <link href="https://cdn.jsdelivr.net/npm/@splidejs/[email protected]/dist/css/splide.min.css" rel="stylesheet">
     <link href="https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap" rel="stylesheet">
     <link href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.4.0/css/all.min.css" rel="stylesheet">
+
+    <!-- PWA -->
+    <link rel="manifest" href="/manifest.json">
+    <meta name="theme-color" content="#7c3aed">
+    <meta name="apple-mobile-web-app-capable" content="yes">
+    <meta name="apple-mobile-web-app-status-bar-style" content="black-translucent">
+    <link rel="apple-touch-icon" href="/static/icons/icon-192x192.png">
     
     <style>
         :root {
@@ -6056,5 +6063,16 @@
     
     <!-- CodeMirror Editor Bundle -->
     <script src="/static/codemirror-editor.js"></script>
+
+    <!-- PWA Service Worker Registration -->
+    <script>
+    if ('serviceWorker' in navigator) {
+        navigator.serviceWorker.register('/sw.js').then(function(reg) {
+            console.log('SW registered:', reg.scope);
+        }).catch(function(err) {
+            console.warn('SW registration failed:', err);
+        });
+    }
+    </script>
 </body>
 </html>