backlog: no freeze signature survives the control; boot-nav blind-tap bug found

docs/re/BACKLOG.md

@@ -952,6 +952,28 @@ premise was wrong.**
   sequential indices); `DisableInterval` is `No` for all 111 S02 squadrons (its
   31 corpus `Yes` records are only S04 and S14, all `GNN***`);
   **`stage\EnumSquadron_Test.tbl` does not exist** — that candidate is dead.
+* 🔴 **(2026-08-25) NO freeze signature survives the control.** Six wait-object
+  captures across ONE healthy run: **12 thread states stable, 13 vary**
+  (`data/waitobj-healthy-stability.txt`). **Every** thread previously reported as
+  a signature is in the VARIES set — including **T68/T69**, which I had kept as
+  "what reproduces across both freezes": they park and unpark during ordinary
+  play, landing on the same objects they hold when frozen. Both frozen diffs are
+  consistent with healthy variation; one-sample-per-state could never separate
+  them. ✅ **Survives:** the 12 stable threads held the same object in all six
+  captures and none moved in either frozen capture, so "not a whole-emulator
+  stall" stands — now resting on the stable set being undisturbed rather than a
+  count. ⚠️ **gdb thread numbers are not comparable across runs** (this run had
+  T132–T142, earlier ones T104–T106) — key on object address or guest tid.
+  **Next: compare DISTRIBUTIONS** — N healthy vs N frozen captures, and call a
+  thread a signature only if its frozen distribution leaves its healthy range.
+* 🐛 **(2026-08-25) Boot-nav bug found and worked around, not yet fixed.** Three
+  consecutive `BOOT FAILED (NO readyroom)` were **not** flakes and **not** input
+  loss — the d-pad and A both work (verified by moving the save cursor and
+  opening the dialog by hand). `wait_screen.sh readyroom 300 --tap A`
+  **blind-taps A**, which answers **NO** on the "Load game?" dialog, bounces back
+  to the save list, then reopens it — a 300 s oscillation. Driving `step up` →
+  `A` by hand reached the ready room in **18 s**. `launch_mission.sh` should not
+  pass `--tap A` while a YES/NO dialog can be on screen.
 * ❔ **What ADVANCES a phase is still unknown** and is not in the data: swept the
   stage record and every table it names plus the `message\` family for
   `interval|time|phase|delay|wave|spawn|arrival|trigger|start|appear|event|condition`