feat(web): ThemeSwitch icon segmented control + theme.* i18n (#59)

web/src/shell/theme-switch.stories.tsx

@@ -0,0 +1,20 @@
+import type { Meta, StoryObj } from '@storybook/react-vite'
+import { expect } from 'storybook/test'
+
+import { ThemeSwitch } from './theme-switch'
+
+const meta = {
+  component: ThemeSwitch,
+  tags: ['ai-generated'],
+} satisfies Meta<typeof ThemeSwitch>
+
+export default meta
+type Story = StoryObj<typeof meta>
+
+export const Default: Story = {
+  play: async ({ canvas }) => {
+    await expect(canvas.getByRole('button', { name: /light/i })).toBeInTheDocument()
+    await expect(canvas.getByRole('button', { name: /dark/i })).toBeInTheDocument()
+    await expect(canvas.getByRole('button', { name: /system/i })).toBeInTheDocument()
+  },
+}