Organize settings into searchable sections with responsive navigation

frontend/index.html

@@ -27,6 +27,7 @@
     <link rel="stylesheet" href="theme-glass.css" />
     <link rel="stylesheet" href="theme-classic.css" />
     <link rel="stylesheet" href="recommendations.css" />
+  <link rel="stylesheet" href="settings-sections.css" />
   </head>
   <body>
     <div class="app">
@@ -652,6 +653,7 @@
     <script src="p2p-transfer.js"></script>
     <script src="async-guard.js"></script>
     <script src="sw-update.js"></script>
+    <script src="settings-sections.js"></script>
     <script src="app.js"></script>
   </body>
 </html>