Expose cancel-safe direct-I/O queues for reading rendered frames and
writing captured frames through the private broker endpoint.
Separate render and capture storage, publish format and state
generations, and preserve local loopback while no broker is bound.
Expose a private, versioned control device that lets the IDD discover
and claim the active audio adapter without using the public PortCls
endpoints.
Restrict access to SYSTEM and UMDF hosts, track adapter and binding
generations, and keep broker failure optional. Reserve data-plane
capabilities without advertising them until PCM queues are available.
