Simplify port mapping: expose 3500 externally, use 3000 internally

- Map host port 3500 to container port 3000
- Keep Next.js on default port 3000 inside container
- Simplifies auth configuration

Dockerfile

@@ -46,9 +46,9 @@ COPY --from=builder /app/prisma ./prisma
 
 USER nextjs
 
-EXPOSE 3500
+EXPOSE 3000
 
-ENV PORT 3500
+ENV PORT 3000
 ENV HOSTNAME "0.0.0.0"
 
 CMD ["node", "server.js"]