MoqInputRelayListenerConfig

Relay-listener mode: subscribe to publishers THROUGH a MoQ relay instead of listening for them. The input dials url (with the same TLS, draft and subscription settings as client mode), sends SUBSCRIBE_NAMESPACE for namespace_prefix, and treats every namespace announced at the relay under that prefix as a connection, exactly as listener mode treats a publisher that connects to it: an on_connection event per announcement, answered with connection_accept / connection_reject, closed with connection_close, and connection_status "connected" / "disconnected". published_namespace is the announced namespace; remote_host is the relay URL.

A namespace withdrawn at the relay (NAMESPACE_DONE), or whose subscriptions have all been ended by the publisher side, is "disconnected". The same namespace announced again later (a reload, a reconnect, another session taking it over) is a NEW connection with a new connection_index. If the relay goes away every connection is "disconnected"; the input redials, and whatever is still announced is raised again. One relay session per input, however many publishers.