Neat https://docs.gitea.com/administration/config-cheat-sheet#ser...

> Enable this to force users to log in to view any page or to use API. It could be set to "expensive" to block anonymous users accessing some pages which consume a lot of resources, for example: block anonymous AI crawlers from accessing repo code pages. The "expensive" mode is experimental and subject to change.

Forgejo doesn't seem to have copied that feature yet