Taps Create new account and opens the first registration screen. Answers its handle.
Types your username and password and taps Log in. Answers where the login leads: the feed, the two-factor approval or method-picker screen, or the last-resort recovery code-entry screen. Each call is one login: two concurrent calls send two logins.
Taps Forgot password and opens the account-recovery search. Answers its handle; fails with the recovery step's typed error when the login home issued no recovery entry.
The actions of LoginHomepageScreen: the methods you call on its handle while the screen is open.
logIn's own transitions to the two-factor screens and the recovery code-entry screen are action edges: the trail records them, but a handle shows no transition that skips the login that issued them.