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/astro.config.mjs

@@ -1,8 +1,15 @@
-import { defineConfig } from 'astro/config';
-import tailwind from '@astrojs/tailwind';
+// @ts-check
 
+import tailwindcss from "@tailwindcss/vite"
+import { defineConfig } from "astro/config"
+import react from "@astrojs/react"
+
+// https://astro.build/config
 export default defineConfig({
-  integrations: [tailwind()],
+  vite: {
+    plugins: [tailwindcss()],
+  },
+  integrations: [react()],
   site: 'https://feynman.is',
   markdown: {
     shikiConfig: {
@@ -12,4 +19,4 @@ export default defineConfig({
       },
     },
   },
-});
+})