UX of Fine-Grained Permissions for AI Agent Authentication

Supporting UX around this topic.

Details coming soon. For now, key links.

gitlab#571819 (closed)

https://gitlab.com/gitlab-org/gitlab/-/issues/505368

https://docs.google.com/spreadsheets/d/1VCnGNavmhloqnIGtQyZUvDLygvnOh_x_DWuEI-o47oQ/edit?gid=0#gid=0

https://docs.google.com/document/d/147N6N4jrQU5YECr6fLxGnm7JHWmjbuEeXnujJrAqQgI/edit?tab=t.0#heading=h.nxdj4gqtwj5d