Why not provide a simple SFTP account for new VCS?

• If we provide a simple sftp account then any group member will be able to remove source history; we don't want that because

  1. We want source code to stay available even if, say, a piece of software decides to go proprietary and remove existing sources.
  2. Group admins won't like intentional or unintentional repository irremediable deletion/corruption by new group members. We should be able to work around that.

• This may help supporting new SCMs, but this actually requires more work than that, e.g. repository web viewers, or upgrading VCS format, etc. Mature/stable SCMs require less time.

• In 2023, we couldn't come up with any way to restrict SFTP access to directories like /etc.