chore: initial scaffold of KDC Design System

Initial repository scaffold:
- design.md (google-labs-code/design.md format) as canonical token + guidelines source
- brand assets, foundations, tokens (W3C-style JSON)
- 12 component primitives, each with labeled anatomy.svg and spec README
- light / dark / high-contrast themes, web/mobile/email/print/presentation templates
- docs (getting started, principles, a11y, voice & tone, contributing)
- runnable web example, token build script stub, CI placeholder

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

themes/README.md

@@ -0,0 +1,11 @@
+# Themes
+
+Theme files override role tokens (`text.default`, `surface.*`, `border.*`)
+without touching the underlying palette. To add a theme, copy `light/theme.json`
+and supply your own values for each role token.
+
+| Theme | File | Use |
+|-------|------|-----|
+| Light | `light/theme.json` | Default product theme. |
+| Dark  | `dark/theme.json`  | Dimmed surfaces, reduced shadow weight. |
+| High Contrast | `high-contrast/theme.json` | Accessibility: 7:1+ contrast. |