The deployment was unreachable because the Next.js server was binding
to localhost:3000 (127.0.0.1) instead of 0.0.0.0, making it only
accessible inside the Docker container.
- Added HOSTNAME=0.0.0.0 to Dockerfile build and runtime stages
- Added HOSTNAME=0.0.0.0 to docker-compose.yml for nextjs service
This allows the server to accept connections from external hosts.