OptionalcurrentUI display string for the player prompt, e.g. "What does Elena do next?".
Do not use this to detect whether it is the player's turn — use
currentSpeaker === userAgentName instead.
The most recent message added to the room
Agent name of the human player's character — compare to currentSpeaker to detect player turns
Agent name of whoever is next to act, or
nullif no specific speaker is designated