nx_remote_worker.nx

nx_remote_worker.nx -- distributed-MIMD pattern: orchestrator dispatches typed tasks to a worker over NetChan; worker computes and returns results. Single-process demo (worker is a spawned thread that listens on TCP); same shape works across hosts when the worker side runs as a remote process. Composes against: [[nx_net_chan_tcp_i64]] -- transport [[thread_clone_native_trampoline]] -- worker thread [[fn_ptr_indirect_call]] -- worker dispatches via typed fn-ptr Worker protocol (per task): 1. orchestrator sends task_id (i64) 2. orchestrator sends arg (i64) 3. worker runs registered_fn(task_id, arg) -> result (i64) 4. worker sends result (i64) 5. orchestrator recvs result Sentinel task_id (-1) signals worker to exit cleanly.