nx_net_chan.nx

nx_net_chan.nx -- typed i64 channel serialised over TCP. Same send/recv semantics as nx_chan (Vyukov MPMC), but the "channel" is a connected TCP socket and each message is 8 bytes big-endian on the wire. Composes with nx_thread_pool / nx_parallel transparently -- a NetChan is a 64-bit handle (the socket fd) that workers can send to or receive from. Wire format: - Each message is a fixed 8-byte big-endian i64 frame. - No length prefix, no checksum, no framing markers. TCP is stream-oriented but with fixed-size frames the receiver can always read exactly 8 bytes per message. - For variable-length payloads (typed structs, byte arrays), use nx_net_chan_blob (queued; length-prefix framed). Endianness: big-endian on the wire (network byte order convention) even though both host and target are likely little-endian. Makes cross-architecture wire compatibility trivial when the cluster becomes heterogeneous. Composes against: [[nx_socket_tcp_loopback]] (transport), [[atomic_intrinsics_real_amo]] (if multiple workers share a NetChan, the underlying socket is the synchronisation point -- kernel handles the lock).