Fix: Load Theme early for onboarding.

index.html

@@ -11,4 +11,9 @@
     <div id="app"></div>
     <script type="module" src="/src/main.tsx"></script>
   </body>
+  <style>
+    html {
+      background-color: #191919;
+    }
+  </style>
 </html>