Add basic auth to all newly created sites by default

I am using the wonderful hestia control panel for the development purposes. So I not to forget to change robots.txt each time I create a copy of a site. I would like to automate this somehow. More to that, I do not want accidentally commit those temporary changes in git.

Putting all the sites under a basic auth protection would work. But doing it manually is the same thing as robots.txt. Is there a way to automatically protect all the newly created sites (for all users or for a user) with apache basic auth (with default login/password)?