Optional
if a step throws: log + continue (true), or ABORT the whole cascade (false — the fail-closed default, so a failed cleanup never silently half-erases and then deletes the user).
diagnostics sink (default console.error).
if a step throws: log + continue (true), or ABORT the whole cascade (false — the fail-closed default, so a failed cleanup never silently half-erases and then deletes the user).