Build a WHEP playback credential (URL + token). Synchronous — no network call.
Tear down a WHEP subscriber. Pass the WhepPlayback returned by
create (or { roomId, participantId }); provide an explicit sessionId
to target a specific session directly.
WHEP egress —
vsdk.whep(standards-based WebRTC pull from a room). Requires an already-active session in the room.