Runtime-agnostic async adapters for Net Lattice.
[from_receiver] bridges the synchronous, blocking
[net_lattice_platform::EventReceiver] onto a futures::Stream. It
deliberately creates one worker thread: std::sync::mpsc::Receiver has no
waker-registration mechanism, so a direct Stream implementation would
block an executor thread. No Tokio, async-std, or smol dependency is
imposed.