Apps declare volumes: name:/path[:ro] (mounts: still accepted). The gateway binds /srv/zero-scale-volumes/<app>/<name> into the unit, running it as a fixed zs-<app> dynamic user so ownership is stable. gateway install creates zero-scale-volumes-pvc; delete-app --purge --delete-volumes removes the data. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_016uKdmp7tLySXvQXALz2x9V