After having put a lot of time into customizing a CiviCRM installation, I want a way to replicate the configuration / customization / installed-extensions, but start from scratch on the contacts (so that newly added contacts -- after the admin contact and organization -- have contact-ids of 3,4,5,...). Deleting all contacts via the UI doesn't seem to "reset" the next-contact ID counter.
Perhaps one way this could be possible is if there were a means by which all configuration / extensions could be backed up and restored, independent of the data in the system (e.g. contacts, memberships, contributions, etc.). Is this possible somehow? Or is there another way to achieve my goal of "starting over" with non-configuration data?