scaffold-project.py and family.py init: --reuse-empty-repo reuses a leg that is empty or whose one commit is the scaffold's own seed, and the ruleset hint offers that re-run, by an operator holding the bypass right, as its one exit, so a project a ruleset refused part-way is finished by one re-run, not refused scaffold-remote-exists for its own legs or sent to a pull request with no base (#462) - #506