Add a non-js placeholder for the theme picker

src/frontend/clientJS/theme-picker.ts

@@ -1,3 +1,6 @@
+// JS is enabled, show theme picker interface
+const elem = document.querySelector(".theme-controls")?.classList.remove('hidden')
+
 // Theme switching functionality
 const LIGHT_THEMES = ['latte', 'solarized-light', 'gruvbox-light'];
 const DARK_THEMES = ['frappe', 'macchiato', 'mocha', 'solarized-dark', 'gruvbox-dark', 'nord', 'dracula', 'one-dark', 'tokyo-night'];

src/frontend/components/theme-picker.tsx

@@ -25,8 +25,9 @@ const THEME_NAMES: Record<string, string> = {
 export function ThemePicker() {
     return (
       <div className="themePicker sheet-background">
+            <noscript>Enable Javascript to select a theme</noscript>
             <label htmlFor="theme" className="hidden">Theme</label>
-            <div className="theme-controls">
+            <div className="theme-controls hidden">
                 <div className="theme-mode-toggle">
                     <button
                         className="mode-btn active"