Codifies the previously-manual tag-based deploy of central on CT 104.
Performs pre-flight drift check, mandatory pg_dump, detached-HEAD
checkout + uv sync, interactive confirm, migration apply, service
restart, and health-check verify. ERR trap prints rollback instructions.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
