A ReprovisionRequested in flight from an old incarnation could reach the NEW child
after HandleRestartDriver swapped it in. In Connecting that child DOES handle
InitializeRequested, so it started a second concurrent InitializeAsync, racing the
#527 dispose-before-overwrite.
Seen RED: InitializeCount == 2 on a child held in Connecting by a gated init
(an already-connected child swallows InitializeRequested and passes vacuously).
The alarm subscribe gated on 'a handle exists', which is correct for an idempotent
re-push and wrong for a deploy that widens/narrows the set. Combined with the
spawn-time desired set, a respawning deploy could latch the PREVIOUS revision's
alarm refs for the life of the connection; sourceNodeIds-filtering drivers
(OpcUaClient/AbCip/Focas) would never deliver the new alarm.
Seen RED: LastSubscribedAlarmRefs stayed [alarmX] after a deploy widening to
[alarmX, alarmY].
Crash seam: the planned null-Snapshot OnDataChange (no SupervisorStrategy fallback needed).
Seen RED with T6 reverted: InitializeCount 1, not 2 — with a preceding ShutdownCount>=1
assertion proving the restart really happened, so the red is not ambiguous with 'never crashed'.
Seen RED against a T3-reverted build: all 4 failed, Created[1].SubscribeCount == 0
on the headline case. 20x isolation run green after the fix was restored.