Fixes a circular dependency: a full stack redeploy tears every service down
before bringing any back up, but claude-agent's image pull goes through
Traefik->Gitea's registry. Self-hosting Traefik in the same stack it fronts
means redeploying this stack could tear down the very route needed to bring
it back. Traefik now lives in ~/traefik/docker-compose.yml as shared infra,
independent of this stack's lifecycle.
william