`wait_on()` now refuses a dead/remote pid (salvaged from #110829); the
judge path cannot raise there — `_apply_wait_directive` calls it inside
`evaluate_after_turn`, so a ValueError would surface as a turn failure.
Check liveness before the call on that path and fall through to the
normal continue decision: the barrier would otherwise lift ~5 s later,
the judge would see the same remote pid and re-park every turn.
teknium1
ee07fcd4d7