Accepts an inbound call. The call transitions through connecting → connected as media negotiation completes.
Without options, the call answers with the media defaults configured on the SignalWire client (typically audio + video). Pass options to narrow what’s offered — for example, accepting a video call with audio only.
answer returns synchronously; observe progression through status$ or answered$.
Optional media constraints for the answer (audio, video, and the input-stream / constraint overrides defined on MediaOptions). When omitted, the client-level defaults apply.
void