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/SonnerContent.stories.tsx

@@ -0,0 +1,40 @@
+/**
+ * Sonner Content Stories
+ * @generated 2025-12-11T14:37:52.640195
+ */
+import type { Meta, StoryObj } from '@storybook/preact';
+import { SonnerContent, type SonnerContentProps } from '../src/atoms/SonnerContent';
+
+const meta: Meta<SonnerContentProps> = {
+  title: '3. Molecules/SonnerContent',
+  component: SonnerContent,
+  tags: ['autodocs'],
+  parameters: {
+    docs: {
+      description: {
+        component: `Auto-generated SonnerContent component
+
+**Classification:** molecule
+**Slots:** icon
+**Figma ID:** 139:11366`
+      }
+    }
+  },
+  argTypes: {
+    type: {
+      control: 'select',
+      options: ['Line and button', 'Lines and button', 'Loading', 'Simple'],
+      description: 'Type variant',
+    },
+  },
+};
+
+export default meta;
+type Story = StoryObj<SonnerContentProps>;
+
+export const Default: Story = {
+  args: {
+    type: 'Line and button',
+    children: 'SonnerContent'
+  },
+};