roomrs-async — runtime-agnostic async facade (명세 §2.4).
Reads and writes are offloaded to a blocking worker pool (or
tokio::task::spawn_blocking with the tokio feature); completion is
signalled through a runtime-neutral oneshot channel, so the returned
futures can be awaited on any executor (tokio, smol, futures::executor).
The pool is selected when the returned future is first polled: with
the tokio feature, a job polled outside a tokio runtime falls back to
the self-managed pool.
Internal crate — use the roomrs facade instead.