Taps I agree: creates the account and answers the server's decision —
Created with the created account and the screen the launch leaves on top
(the feed), ChallengeRequired with the created account and no launch (the
challenge is its own flow), or PartiallyCreated when the server gave
nothing to complete the account with. A launch failure after the account
exists is RegisteredButLaunchFailedError, which keeps the created account;
the screen stays on top for retryLaunch(). Calling it twice sends two
creations.
Runs the launch again after agree() answered RegisteredButLaunchFailedError
(the same action works on a restored checkpoint of that screen). It sends no
registration request and answers the launch's first screen, or the launch's
own error.
The actions of RegistrationTermsOfServiceScreen: the methods you call on its handle while the screen is open.