re: target preference works; the blocker is now combat effectiveness, not RE

pilot.py gained SYLPH_PREFER, a unit-name substring whose matches get their
target score multiplied by 0.05 while everything else is multiplied by 4.0. With
SYLPH_PREFER=e010 a clean 320 s run, zero stalls by the witness, killed eight
turrets and two Attacker_S.

The preference is real -- e010 kills went from roughly one across all previous
runs to two in a single run -- but it is weak. Turrets still outnumber attackers
four to one in the kill log, because target commitment and simple proximity keep
pulling the nose back to them, and phase 1 fields 108 turret craft against 16
attackers. Deployed stayed at 41 throughout, so no phase advance.

That quantifies the blocker. Clearing the marked attackers means destroying 16
craft, and at two per 320 s that is about 2560 seconds, roughly 43 minutes of
continuous verified-live flight across many chained attaches, against a freeze
rate of about two runs in five.

This is no longer a reverse-engineering problem. Everything needed to observe
the phase advance is built and validated -- the roster-to-craft link, the
liveness read, the stall witness, chained attaches and the discard rule. What is
missing is a pilot good enough to complete the mission objective, which is
game-playing work with an uncertain payoff.

The choice is recorded rather than made, because it is about how much effort one
confirmation is worth rather than a technical unknown: invest in the pilot,
accept the static answer where only the trigger is inferred rather than
observed, or attempt one very long chained run betting against the freeze rate.

docs/re/BACKLOG.md

@@ -546,6 +546,20 @@ search cannot find a *schedule*.
   line in every run reads `UN_e007_ADAN_Turret`, because `SYLPH_HUNT`/`KEEPOUT`
   were built for turrets. **42 kills were the wrong 42.** **Test: a pilot that
   prioritises `e010` over `e007`**, watching `deployed` jump from 41.
+* ✅🚧 **(2026-08-24) `SYLPH_PREFER` works; the blocker is now COMBAT, not RE.**
+  Preference knob added (matching units ×0.05, others ×4.0). One clean 320 s run
+  (**0 stalls**): 8 turret kills vs **2** `e010` — real effect (was ~1 across ALL
+  prior runs) but weak; commitment + proximity keep pulling back to turrets, which
+  outnumber attackers 108:16 in craft. `deployed` stayed **41**, no advance.
+  🚧 **Quantified blocker:** phase 1 fields **16** `Attacker_S` craft; at 2 per
+  320 s clearing them needs **~2560 s ≈ 43 min** of verified-live flight across
+  many chained attaches, against a ~2-in-5 freeze rate.
+  **Everything needed to OBSERVE the advance is built and validated** — roster
+  link, liveness, stall witness, chained attaches, discard rule. What is missing
+  is a pilot good enough to finish the objective. **User's choice:** (1) invest in
+  the pilot (game-playing, uncertain); (2) accept the static answer (structure,
+  rosters, routes, objective texts all decoded and cross-confirmed; only the
+  *trigger* is inferred); (3) one 40+ min chained run betting against freezes.
   🔴 `SYLPH_HZ=3` refuted as a lever: it gave the LOWEST frame rate (8/s) with the
   most kills, so pilot polling is not the throttle.
 * ~~🚧 BLOCKER: t=210/240 unreachable in one turn~~ — **superseded, see above**;