Run 2 put the inducer on from flight start and froze ~96s in, against 670s
clean with it off -- n=2, contrast sharp, confounder (elapsed mission time)
still untouched.
Withdraws last iteration's 'T74/T75 move off a semaphore onto an event' as the
signature to chase: it does not reproduce. In run 2 they are on XEvent while
HEALTHY and stay there. The healthy state varies between instants, so a
one-sample-per-state diff cannot separate a freeze transition from ordinary
variation -- I read a difference of samples as a difference of states.
Reproduces across both: T68 and T69 go from not-waiting to waiting, T69 on a
semaphore and T68 on an event both times. And 21 of 24 threads unchanged in run
2 (17 of 24 in run 1), so 'not a whole-emulator stall' now has two independent
captures behind it.
Next: repeat the capture several times within one healthy run to establish which
thread states are stable before reading any frozen diff.
