OptionalCauseThe original error, when available.
OptionalDeviceFor a device error about one device: which, and what the user asked of it. Absent on other errors, and on a
device error about no one device (listing the devices).
A stable category for programmatic handling. 'agent-vision': the server could not record whether the user lets
agents see their camera and shared screen.
A human-readable message.
A normalized error surfaced by the room (connection failure, device error, publish failure).