Currently, visiting e.g. https://en.wikipedia.org/wiki/Special:Manage_Two-factor_authentication when no 2FA methods are set up only displays a button to enable TOTP, but does not display a button to enable WebAuthn. To set up WebAuthn, you have to go to https://auth.wikimedia.org/enwiki/wiki/Special:Manage_Two-factor_authentication , which is not very discoverable (there's banner that links there and sort of explains this, but it's not very clear). This is because the user must be on the auth.wm.o domain for the JS that sets up WebAuthn to work, but this isn't a very user friendly experience.
To make this more user-friendly, we should automatically redirect to the auth domain if the user tries to view this special page on a non-auth domain.
- When the user tries to view Special:Manage_Two-factor_authentication not on the auth domain, don't display the special page, but redirect to the auth domain
- Update the link to this special page on the preferences page to point directly to the auth domain, so that we don't link to a page that will then immediately redirect
- These changes should only be made on SUL wikis; non-SUL wikis should work as they do now, and not redirect to the auth domain