Rebuild website from scratch on Tailwind v4 + shadcn/ui

- Fresh Astro 5 project with Tailwind v4 and shadcn/ui olive preset
- All shadcn components installed (Card, Button, Badge, Separator, etc.)
- Homepage with hero, terminal demo, workflows, agents, sources, compute
- Full docs system with 24 markdown pages across 5 sections
- Sidebar navigation with active state highlighting
- Prose styles for markdown content using shadcn color tokens
- Dark/light theme toggle with localStorage persistence
- Shiki everforest syntax themes for code blocks
- 404 page with VT323 font
- /docs redirect to installation page
- GitHub star count fetch
- Earthy green/cream oklch color palette matching TUI theme

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

website/public/favicon.svg

@@ -0,0 +1,3 @@
+<svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 36 36">
+  <path fill="#000" d="M22.25 4h-8.5a1 1 0 0 0-.96.73l-5.54 19.4a.5.5 0 0 0 .62.62l5.05-1.44a1 1 0 0 0 .67-.55L18 14l4.41 8.76a1 1 0 0 0 .67.55l5.05 1.44a.5.5 0 0 0 .62-.62l-5.54-19.4a1 1 0 0 0-.96-.73Z"/>
+</svg>