- a child is fds: Child {id, stdin, stdout, stderr}, driven by the
existing net verbs (echo leg proves cat round-trip through write_dl/
read_dl); caller owns the fds, the runtime owns pid + pidfd
- wait_dl parks on the pidfd: code on exit, nil at the deadline with the
child untouched; one waiter per id, a second refuses by name; stale
ids refused via a generation counter in the handle
- proc.signal through pidfd_send_signal; actor_die kills the streaming
children the dying actor owns; dead fibers cannot linger as waiters
- ids 97-107 registered wholesale (wob.h, loader arities, dispatch
bound); Child + Signal predeclared records in types.ml; unimplemented
ids trap at the default case until their task lands
- test_proc 168/0 (echo, wait trio, one-waiter refusal, 200-round churn
fd-flat), suite ASan clean, woc-test green
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
(cherry picked from commit 9be87f159f1bf9cdd509ceed160e7ea518fde46c)