chore: upgrade Tailwind CSS to v4

- Replace @tailwind directives with @import "tailwindcss"
- Switch PostCSS plugin to @tailwindcss/postcss
- Add @theme inline block mapping CSS vars to v4 theme tokens
- Move accordion keyframes/animations to globals.css
- Remove tailwind.config.ts and tailwindcss-animate (no longer needed)
- Update components.json to clear config path

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

next-env.d.ts

@@ -1,6 +1,6 @@
 /// <reference types="next" />
 /// <reference types="next/image-types/global" />
-import "./.next/dev/types/routes.d.ts";
+import "./.next/types/routes.d.ts";
 
 // NOTE: This file should not be edited
 // see https://nextjs.org/docs/app/api-reference/config/typescript for more information.