docs(issues): close #368 (fixed in b7f59923); file #370 — the headless jump-airborne timeout survives single-threading, so it was never a threading artifact

#368's entry now records the fix mechanism (dedicated
acdream-headless-update thread owning Start + every scheduler turn;
synchronous TimeProvider-timer scheduler loop; guard untouched, zero
shared Runtime changes) and the 3/3 live-ACE verification vs the 3/3
pre-fix quarantines. The #365 entry and diagnosis doc get dated
pointers: their open question is answered — the airborne residual
persists with threads provably single, refuting the
unsynchronized-thread hypothesis — and is split off as #370 with the
evidence and starting points.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/research/2026-08-10-365-headless-hydration-diagnosis.md

@@ -447,3 +447,16 @@ Every real (unmodified) run's session tore down gracefully
 (`[session] graceful logout confirmed`, zero entities/leases at the final
 `disposed` sample) regardless of which way it exited — `testaccount` was
 never left in a stuck state by this work.
+
+## 9. ADDENDUM (2026-08-10, #368 fix session)
+
+#368 is CLOSED at `b7f59923`: one dedicated headless update thread now owns
+Start, every scheduler turn, and the post-loop captures; the scheduler loop
+is synchronous with TimeProvider-timer event waits (no `Task.Delay`
+resumption migration; zero shared Runtime changes). Three live jump-probe
+runs on the fixed tree each crossed `[wake] begin gen=1` cleanly with
+204–205 hydrated entities and graceful exits. The §8 open question is now
+answered: the `airborne-transition True` timeout PERSISTS 3/3 with threading
+provably single, so the "downstream artifact of the unsynchronized-thread
+condition" hypothesis is refuted — the residual is a distinct pre-existing
+defect, filed as #370.