re: motion-independent liveness probe; n looks like craft-per-member

entities2.moving() finds entities by displacement between two samples, so
anything stationary is invisible -- the entire explanation for the +/-10 swing
that made the previous run's count useless. liveness_probe.py enumerates by
definition pointer over the entity heap instead, moving or not, and reads hull
as f32 at position+0x154. The series is monotone rather than oscillating:
298 -> 280 over 164 s, with the decline matching the 18 disappearance events
exactly.

The hunting pilot does kill: one hull crossing caught directly, an
e010_ADAN_Attacker_S at t=57 s. The previous run's worry that SYLPH_HUNT shoots
but never destroys anything is settled.

Recorded as a non-result so the next run does not misread it: zero births in
164 s does NOT favour either wave model. The roster finding already established
that every participant is allocated at mission load, so neither a clock nor an
event model would produce an allocation. An arrival must be a state change on an
existing entity.

The mystery member field n now has a candidate meaning: the number of craft a
roster member spawns. Static sum(n) for turrets is 216 against 214 sites found,
with the count already falling before the first sample, where Count alone
predicts 21 -- off by an order of magnitude.

Not promoted, and the reason is a confound in my own measurement rather than the
data: the probe counts definition-pointer SITES, not entities. The player is one
member and yields two sites, and DeltaSaber_T yields exactly double its sum(n),
so some entity types hold several pointers to their definition. Until sites are
collapsed into distinct entities the turret match could be a coincidence between
a x1 multiplicity and a x1 ratio. The capital-ship rows undershoot for a
separate and expected reason: phases 2 and 3 have not started.

docs/re/BACKLOG.md

@@ -320,6 +320,16 @@ search cannot find a *schedule*.
   record per member (n=1, NOT promoted; the refutation needs another stage's
   save, which we do not have — only slot 01 / Stage 02 exists).
   ❔ Still unmeasured: whether the timetable's `t` is frames or seconds.
+* ✅🟡 **Motion-independent liveness probe works; `n` is probably craft-per-member**
+  (2026-08-24) — [`mission-liveness-probe.md`](mission-liveness-probe.md).
+  Enumerating by definition pointer instead of by motion removes the ±10 noise
+  (monotone 298→280). The hunting pilot **does** kill (hull crossing at t=57s).
+  🔴 "No births in 164 s" does NOT separate the wave models — everything is
+  pre-allocated, so an arrival must be a STATE CHANGE, not an allocation.
+  🟡 Turret `sum(n)`=216 vs 214 sites found (vs `Count`=21) suggests the mystery
+  member field `n` is the craft count per member — NOT promoted: the probe counts
+  definition-pointer *sites*, and the player (1 member → 2 sites) proves some
+  entities hold several. **Next: collapse sites into entities, then re-test.**
 * 🟡 **COMPETING MODEL (user, 2026-08-24): waves are event-gated, not
   clock-driven** — released by kills/objectives rather than at a fixed time, with
   the route's start time being a post-trigger delay. Fits the evidence better: