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/fonts/fonts.css

@@ -0,0 +1,18 @@
+/* KDC Design System — font-face declarations.
+   Self-host these files from /assets/fonts/. */
+
+@font-face {
+  font-family: "Inter";
+  font-style: normal;
+  font-weight: 100 900;
+  font-display: swap;
+  src: url("./Inter/Inter-Regular.woff2") format("woff2");
+}
+
+@font-face {
+  font-family: "Roboto Mono";
+  font-style: normal;
+  font-weight: 400 700;
+  font-display: swap;
+  src: url("./Roboto-Mono/Roboto-Mono-Regular.woff2") format("woff2");
+}