- Upgrade tailwindcss to v4, add bun-plugin-tailwind
- Remove postcss.config.js and tailwind.config.ts (not needed in v4)
- Add bunfig.toml with [serve.static] plugin config
- Update globals.css to use @import 'tailwindcss' and @theme block
- Fix server to use development mode and remove problematic fetch handler
- Import CSS in main.tsx instead of linking in HTML
- Update AGENTS.md with Bun.serve() and Tailwind v4 notes