Adding a passkey makes it mandatory as MFA on other devices

Even in the more useful context of passkeys that are stored on mobile devices, this setup has made it impossible to log in on Firefox, since Firefox (at least on desktop) doesn't support any type of passkey other than physical security keys or hardware passkey interpreters. Since making an exception doesn't make sense, I think it may be necessary to allow authentication from outside sessions on all platforms instead of just the desktop app.