Fix Vercel deployment: Tailwind CSS, API endpoints, and Bun runtime

- Add missing /api/patterns.js endpoint (was causing 404)
- Fix Tailwind CSS: compile with @tailwindcss/cli instead of Bun virtual module
- Update API handlers to use standard Vercel function export format
- Configure vercel.json with proper Bun runtime (runtime: "bun@1")
- Add @tailwindcss/cli to devDependencies
- Add generated styles.css to .gitignore

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

package.json

@@ -23,6 +23,7 @@
   "author": "Paul Bakaus",
   "license": "SEE LICENSE FILE",
   "devDependencies": {
+    "@tailwindcss/cli": "^4.1.18",
     "bun-plugin-tailwind": "^0.1.2"
   },
   "dependencies": {