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>

assets/patterns/dot-grid.svg

@@ -0,0 +1,6 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 40 40" width="40" height="40">
+  <defs><pattern id="d" width="40" height="40" patternUnits="userSpaceOnUse">
+    <circle cx="2" cy="2" r="1.5" fill="#D9DCE3"/>
+  </pattern></defs>
+  <rect width="40" height="40" fill="url(#d)"/>
+</svg>