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/elevation.json

@@ -0,0 +1,9 @@
+{
+  "elevation": {
+    "0": { "shadow": "none" },
+    "1": { "shadow": "0 1px 2px rgba(17,24,39,0.06)" },
+    "2": { "shadow": "0 4px 12px rgba(17,24,39,0.10)" },
+    "3": { "shadow": "0 16px 32px rgba(17,24,39,0.16)" },
+    "4": { "shadow": "0 24px 48px rgba(17,24,39,0.20)" }
+  }
+}