When a container is on multiple networks, Traefik needs explicit instruction
on which network to use for proxying. Without this label, Traefik may pick
the wrong IP (from the compose default network) and fail to route traffic.
Co-Authored-By: Paperclip <noreply@paperclip.ing>
Coolify's Traefik is on the 'coolify' Docker network. Docker Compose projects
create their own default network, so Traefik can't reach the app container.
Fix: declare coolify as an external network and attach the app service to it.
Co-Authored-By: Paperclip <noreply@paperclip.ing>