The bridge session context (agent id/name + user + provider).
The live realtime session to hand to AIBridgeEngine.StartBridgeSession.
When the agent can't be resolved, has no DriverClass, the driver can't be instantiated, or no usable Realtime model is configured (surfaced from BaseAgent.StartBridgeRealtimeSession).
Opens a raw IRealtimeSession for the agent named in
ctx. Bind this onto a bridge's session-factory seam (e.g.LiveKitAgentRoomCoordinator.Instance.SetSessionFactory(CreateBridgeRealtimeSession)).