chore(config): Remove PORT environment variable configuration

- Remove PORT environment variable comment from .env.example
- Update start script to use hardcoded port 3000 instead of environment variable
- Simplify server configuration by removing optional PORT override

package.json

@@ -6,7 +6,7 @@
   "scripts": {
     "dev": "next dev --turbopack",
     "build": "next build",
-    "start": "next start -p ${PORT:-3000}",
+    "start": "next start -p 3000",
     "lint": "eslint",
     "db:generate": "drizzle-kit generate",
     "db:push": "drizzle-kit push",