- ceiling: 32 fibers hold live sleepers; the 33rd spawn traps WO_T_IO
naming the ceiling; destroy sweeps all 32 (waitpid -1 = ECHILD after)
- unwind: a fiber parked on a live child is reaped at main's return and
the child dies with it (nchildren 0 straight after the call)
- churn: one thousand sequential `true` runs through a bytecode loop —
fd count flat, every slot released
- stop: SIGTERM from a helper 200 ms into a sleep-10 child answers rc 1
(STOPPED) with no surviving child
- test_proc 128 pass 0 fail in 2.6 s, suite ASan clean
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>