Match the browser/OS chrome to the theme and clear the status bar

The app now sets theme-color, color-scheme and the page background from the chosen theme,
so the iPad status-bar area no longer shows a light band over a dark theme. Every top bar
leaves room for the status bar via a safe-top class (replacing a rule that padded every
<header>). Install defaults match the paper theme.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

index.html

@@ -9,7 +9,7 @@
     <link rel="manifest" href="/manifest.json" />
 
     <!-- Theme / status bar -->
-    <meta name="theme-color" content="#0f172a" />
+    <meta name="theme-color" content="#f1ece0" />
 
     <!-- iOS PWA -->
     <meta name="apple-mobile-web-app-capable" content="yes" />
@@ -20,7 +20,7 @@
     <!-- Fallback icon for browsers -->
     <link rel="icon" type="image/png" sizes="192x192" href="/icon-192.png" />
   </head>
-  <body class="bg-slate-50 text-slate-900">
+  <body>
     <div id="root"></div>
     <script type="module" src="/src/main.jsx"></script>
   </body>