add liveline page: recreation of benji.org/liveline editorial design

Recreates the benji.org/liveline page in the website folder using React,
Tailwind, and the same editorial design system. Charts are replaced with
static SVG placeholders.

Typography:
- Inter variable font from rsms.me (same source as next/font)
- font-weight 475 body, 560 headings, font-optical-sizing: auto
- 14px body, 20px line-height, -0.09px letter-spacing
- Near-black text rgb(17,17,17), 40% opacity secondary
- Display P3 accent colors with @supports fallback

Layout:
- 550px narrow content column, fixed TOC sidebar
- Stagger-in entrance animation with cascading delays
- Fixed header fade gradient (multi-stop white-to-transparent)
- Scroll-spy TOC highlighting via IntersectionObserver

Code blocks:
- Prism.js syntax highlighting with GitHub-light color palette
- Line numbers column with 20px right padding
- 12px / 18px font size

Props tables, dividers, captions, code blocks, bullet lists all
styled to match the original computed values.

website/package.json

@@ -16,11 +16,13 @@
     "@react-router/node": "^7.11.0",
     "@sentry/node": "^10.32.1",
     "@tailwindcss/typography": "^0.5.19",
+    "@types/prismjs": "^1.26.6",
     "@vercel/react-router": "^1.2.4",
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
     "isbot": "^5.1.32",
     "lucide-react": "^0.562.0",
+    "prismjs": "^1.30.0",
     "react": "^19.2.3",
     "react-dom": "^19.2.3",
     "react-router": "^7.11.0",