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>

brand/icon-set/kdc-glyph.svg

@@ -0,0 +1,4 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 240 80" width="240" height="80" role="img" aria-label="K">
+  <rect width="240" height="80" fill="#0B5FFF"/>
+  <text x="120" y="46" text-anchor="middle" font-family="Inter, Arial, sans-serif" font-size="20" font-weight="700" fill="#FFFFFF">K</text>
+</svg>