Backend deploy target is self-hosted Docker (VPS / Kubernetes / Docker
Engine), not Cloud Run. Add a multi-stage Dockerfile (Node 20, bcrypt
compiled in build stage, non-root runtime), .dockerignore, a staging
docker-compose, and DEPLOY.md covering install, build, migrate, run, and
log mapping/rotation. Pin engines.node>=20. Update deployment.md runbook
and backend/CLAUDE.md infra line off Cloud Run.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
