Review follow-up: the blanket 10s default correctly targets worker-thread
cold-start races (starting, first-script-line, async child-registration
messages — genuinely CPU-bound under CI contention), but four waits assert
something different — that the HOST reacted PROMPTLY to an event that
already happened (a settled result, an observed worker death). Those had no
cold-start left to wait on, so the generous default just widened the window
a real regression could hide in.
Verified by injecting a 6s delay into the settle-reap's abort call: the
un-overridden helper's test still passed in ~6s. The same mutation now fails
in ~1s with the explicit 1000ms override restored on all four sites (the
abort-on-settle test's own assertion, the two worker-death cancel/dispose
reap checks, and the dispose-ack-race check). The other 12 waits keep the
10s default — they run BEFORE a result is awaited, waiting on the worker to
actually start rather than on a host reaction. Doc comment corrected to
describe the split instead of claiming every wait is a cold-start race.