manual retrigger of post-install scripts

[kallisti5]

There doesn't appear to be a way to "manually reset" post-install scripts. While I can "touch ~/config/settings/first_login" to re-run the first_login scripts, there is no clear way to reset post-install scripts (like sshd generating host keys).

The usecase is sysprepping haiku installs (aka, we want the system to regenerate host keys on first boot... so the ssh host keys are manually erased before shutting down the host and making an image of it.

There should be a way to "manually re-trigger all post-install scripts on boot", much like the existence of "first_login in ~/config/settings/first_login