Apply neo-kinpaku design system and improve live picker UX

Restyle the live picker to match the site kinpaku kit, persist pick mode
in localStorage, fix DESIGN.md color swatches in the parser, and land the
neo-kinpaku site refresh with new tokens, assets, palette script, and
detector rules.

Co-authored-by: Cursor <cursoragent@cursor.com>

package.json

@@ -85,8 +85,10 @@
     "ai": "^6.0.168",
     "archiver": "^7.0.1",
     "astro": "^6.2.1",
+    "fontkit": "^2.0.4",
     "modern-screenshot": "^4.7.0",
     "motion": "^12.38.0",
+    "opentype.js": "^2.0.0",
     "playwright": "^1.59.1",
     "wrangler": "^4.85.0",
     "zod": "^4.3.6"