Setup's job is to write a project's Docker files, and --no-docker-overwrite is
how a caller declines that, so a re-run must still replace what it finds. The
publisher's new default is the opposite — it will not silently revert a file
somebody has since tuned — which is right for vortos:docker:publish against a
mature app and would otherwise turn setup into a no-op. Backups are unaffected.

Split from 79e6ff7710024b35e4acb95eb79fc07b5ec82357