Something still feels off about this.

Are you sure desktop code should be calling this? AFAIK, the TermEvent enum is a bunch of events that our web SSH console depends on. I wouldn't expect the desktop player to depend on any term events since it is not a terminal.

If your intent is some refactoring so that SSH and desktop MFA share more code I think that's a fine goal, but I think the abstraction is probably not quite right. I don't think desktop code should depend on TermEvent.

I didn't make any significant refactor to the Desktop session MFA code, it was already using useMfa, which took Tty or EventEmitterMfaSender as an argument (tdpClient implements EventEmitterMfaSender). I renamed it to useMfaTty or useMfaEmitter so that I could make useMfa more generally usable.

EventEmitterMfaSender just represents the websocket used in WebUI sessions to send MFA challenges from the proxy and retrieve a challenge response from the client. Tty extends that for Terminal purposes. I can take a stab at renaming to make this more clear.

@avatus Can you help provide any more clarification? It is a dense section of the code base.

I think this is a result of poor naming/abstractions from the past. desktop and ssh docs both implemented the old EventWebAuthnEmitter or whatever it was called, which had a single non-implemented sendWebauthn method that tty and tdpClient had to implement themselves. And we've since updated it from useWebauthn to useMfa but that weird abstraction layer should probably just go imo, we don't need it. Outside of this PR probably