Initial commit: FA 2.0 Design System foundation

Token pipeline (Style Dictionary v4, DTCG format):
- Primitive tokens: colour palettes (brand, sage, neutral, feedback),
  typography (3 font families, 21-variant type scale), spacing (4px grid),
  border radius, shadows, opacity
- Semantic tokens: text, surface, border, interactive, feedback colours;
  typography roles; layout spacing
- Component tokens: Button (4 sizes), Input (2 sizes)
- Generated outputs: CSS custom properties, JS ES6 module, flat JSON

Atoms (3 components):
- Button: contained/soft/outlined/text × primary/secondary, 4 sizes,
  loading state, underline for text variant
- Typography: 21 variants across display/heading/body/label/caption/overline,
  maxLines truncation
- Input: external label, helper text, error/success validation,
  start/end icons, required indicator, 2 sizes, multiline support

Infrastructure:
- MUI v5 theme with full token mapping
- Storybook 8 with autodocs
- Claude Code agents and skills for token/component workflows
- Design system documentation and cross-session memory

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.storybook/main.ts

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+import type { StorybookConfig } from '@storybook/react-vite';
+
+const config: StorybookConfig = {
+  stories: ['../src/**/*.stories.@(ts|tsx)'],
+  addons: [
+    '@storybook/addon-essentials',
+    '@storybook/addon-designs',
+  ],
+  framework: {
+    name: '@storybook/react-vite',
+    options: {},
+  },
+  docs: {
+    autodocs: 'tag',
+  },
+  viteFinal: async (config) => {
+    // Inherit aliases from vite.config.ts automatically via react-vite framework
+    return config;
+  },
+};
+
+export default config;

.storybook/preview-head.html

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+<link rel="preconnect" href="https://fonts.googleapis.com" />
+<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin />
+<link
+  href="https://fonts.googleapis.com/css2?family=Montserrat:wght@400;500;600;700&family=Noto+Serif+SC:wght@400;600;700&display=swap"
+  rel="stylesheet"
+/>

.storybook/preview.tsx

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+import React from 'react';
+import type { Preview } from '@storybook/react';
+import { ThemeProvider } from '@mui/material/styles';
+import CssBaseline from '@mui/material/CssBaseline';
+import { theme } from '../src/theme';
+import '../src/theme/generated/tokens.css';
+
+const preview: Preview = {
+  decorators: [
+    (Story) => (
+      <ThemeProvider theme={theme}>
+        <CssBaseline />
+        <Story />
+      </ThemeProvider>
+    ),
+  ],
+  parameters: {
+    controls: {
+      matchers: {
+        color: /(background|color)$/i,
+        date: /Date$/i,
+      },
+    },
+  },
+};
+
+export default preview;