Create new workspace, and more optimizations

src-web/components/ToggleThemeButton.tsx

@@ -0,0 +1,15 @@
+import React from 'react';
+import { useTheme } from '../hooks/useTheme';
+import { toggleAppearance } from '../lib/theme/window';
+import { IconButton } from './core/IconButton';
+
+export function ToggleThemeButton() {
+  const { appearance, toggleAppearance } = useTheme();
+  return (
+    <IconButton
+      title={appearance === 'dark' ? 'Enable light mode' : 'Enable dark mode'}
+      icon={appearance === 'dark' ? 'moon' : 'sun'}
+      onClick={toggleAppearance}
+    />
+  );
+}