feat(brand): adopt official Kode brand guidelines

- Brand palette: purple #6B35A7 (primary), #000000 (ink), #FFFFFF, #F5F4F0 (canvas)
- Typography: Manrope (UI, 200-800) + Opificio Bold (wordmark/display); drop Inter
- design.md: add wordmarkSecondary token, new display scale (Opificio 72/80)
- foundations: refresh swatches and typography README to match guidelines
- assets/fonts: replace Inter folder with Manrope; add Opificio cuts (Bold/Rounded/Regular)
- fonts.css: register Manrope variable + Opificio cuts; keep Roboto Mono for code only
- examples/web: render the kode wordmark lockup on the off-white canvas
- brand-guidelines: real specs (lockup, palette, typography, logo variant rules)
- README: add brand-at-a-glance, bump version to beta

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

assets/fonts/Manrope/README.md

@@ -0,0 +1,17 @@
+# Manrope
+
+Primary UI typeface for Kode Design Consultants — used for all headings, body
+copy, captions, and the secondary line of the wordmark lockup.
+
+Drop the licensed binaries here:
+
+- Manrope-Variable.woff2 (preferred, weights 200–800)
+- Manrope-ExtraLight.woff2 (200) — secondary wordmark line
+- Manrope-Regular.woff2 (400)
+- Manrope-Medium.woff2 (500)
+- Manrope-SemiBold.woff2 (600)
+- Manrope-Bold.woff2 (700)
+- Manrope-ExtraBold.woff2 (800)
+
+Manrope is licensed under the SIL Open Font License — include LICENSE.txt
+alongside the binaries.