feat(cast): complete quinn.cast deployment surface (deploy-captain agent delivery)
- Full production deploy.sh (rollback, secrets, docker compose relay stack, health with explicit exit/HTTP report, --name/doctl resolution, bootstrap, nginx+certbot on standalone droplet)
- data/ (docker-compose, env example, mediamtx.yml)
- nginx/prod.conf (standalone droplet)
- services.yaml + systemd wrapper
- bootstrap script
- Narrow runner updates: ./run header + scripts/run/deploy.sh (deploy:cast case)
Modeled exactly on quinn.ai/quinn.m patterns. Scoped to agent's exclusive paths. Self-verified (health 200 sim + real controller, bash -n, fresh main).
Per approved plan + user 'merge to main + multiple agents'.