feat(dss-ui): Button component with design tokens only

- Button.css uses only CSS custom properties, no fallbacks
- Token validator now blocks hardcoded values (strict_mode: true)
- Hook scripts converted from ESM (.js) to CommonJS (.cjs)
- Storybook unified config with HMR disabled for nginx proxy
- Added dss-ui package with Figma-synced components and stories

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

packages/dss-ui/stories/BasicTableHeader.stories.tsx

@@ -0,0 +1,40 @@
+/**
+ * Basic Table Header Stories
+ * @generated 2025-12-11T14:37:52.647707
+ */
+import type { Meta, StoryObj } from '@storybook/preact';
+import { BasicTableHeader, type BasicTableHeaderProps } from '../src/atoms/BasicTableHeader';
+
+const meta: Meta<BasicTableHeaderProps> = {
+  title: '4. Organisms/BasicTableHeader',
+  component: BasicTableHeader,
+  tags: ['autodocs'],
+  parameters: {
+    docs: {
+      description: {
+        component: `Auto-generated BasicTableHeader component
+
+**Classification:** organism
+**Slots:** None
+**Figma ID:** 164:18430`
+      }
+    }
+  },
+  argTypes: {
+    cellType: {
+      control: 'select',
+      options: ['Heading'],
+      description: 'Cell Type variant',
+    },
+  },
+};
+
+export default meta;
+type Story = StoryObj<BasicTableHeaderProps>;
+
+export const Default: Story = {
+  args: {
+    cellType: 'Heading',
+    children: 'BasicTableHeader'
+  },
+};