Rewrite site from Next.js 12 to Astro 5

- Switch from yarn to pnpm, replace lockfile
- Add Astro with Cloudflare Pages adapter and Tailwind CSS v4
- Move content into Astro content collections (src/content/)
- Define Zod schemas for transcripts, blog, and md-pages collections
- Port rehype plugins (timecodes, collapsible lists) to src/plugins/
- Add BaseLayout with nav, global styles, and markdown prose styles
- Create proof-of-concept routes for all content types
- Add index pages for /transcripts and /blog
- Add /guidelines -> /conduct redirect and /tmir external redirect
- Move old Next.js pages to _nextjs-pages/ (outside src/)
- Add frontmatter to roles.md (only content file needing modification)
- Upgrade remark-gfm v4 and rehype-slug v6 for unified v11 compat
- Update .gitignore for Astro, remove stale yarn/Next.js git hooks

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: vcarl

.gitignore

@@ -2,39 +2,28 @@
 
 # dependencies
 /node_modules
-/.pnp
-.pnp.js
-pnpm-lock.yaml
 
-# testing
-/coverage
-
-# next.js
-/.next/
-# next sitemap
-sitemap*
-robots.txt
+# astro
+dist/
+.astro/
 
 # misc
 .DS_Store
 *.pem
 
 # debug
 npm-debug.log*
-yarn-debug.log*
-yarn-error.log*
 
 # local env files
 .env.local
 .env.development.local
 .env.test.local
 .env.production.local
-
-# vercel
-.vercel
+.env
 
 .netlify
-.env
 
 # typescript
 *.tsbuildinfo
+
+tmp.md