docs(deploy): add deploy runbook and post-pull recreate script #767

Problem

The webhook pull stack loads new relay images but does not recreate the container or run migrations. Operators need a clear manual deploy procedure.

Proposal

• Add docs/DEPLOY-RUNBOOK.md (deploy, verify /readyz, rollback)
• Add deploy/recreate-relay.sh (migrate -> recreate relay -> wait for readiness)
• Link from deploy/README.md