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>

.claude/skills/build-atom/SKILL.md

@@ -0,0 +1,22 @@
+---
+name: build-atom
+description: Build an atom component (Button, Input, Typography, etc.)
+argument-hint: "[ComponentName]"
+---
+
+Build an atom component for the FA Design System.
+
+Use the component-builder agent to handle this task. The user wants to build the following atom component:
+
+**Component:** $ARGUMENTS
+
+**Instructions for the agent:**
+1. Read all memory files and conventions before starting
+2. Check `docs/memory/component-registry.md` to confirm the component is planned
+3. Create the component in `src/components/atoms/{ComponentName}/`
+4. Include: `{ComponentName}.tsx`, `{ComponentName}.stories.tsx`, `index.ts`
+5. Follow all rules in `docs/conventions/component-conventions.md`
+6. ALL visual values MUST come from the MUI theme — never hardcode
+7. Write comprehensive Storybook stories covering all states
+8. Verify the component renders in Storybook
+9. Update all memory files when done