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>

tokens/breakpoints.json

@@ -0,0 +1,9 @@
+{
+  "breakpoints": {
+    "sm":  "640px",
+    "md":  "768px",
+    "lg":  "1024px",
+    "xl":  "1280px",
+    "2xl": "1536px"
+  }
+}