Z: P10 -- what Auto Resolve should cost, written before the click

The turn-54 End Turn stopped on a Von Neumann encounter at Gallandro. That is
the workload the finding says does not exist and lane J asks for: every
encounter measured so far had the no-battle flag set, so the combat resolver
has never run under an instrument.

Three falsifications, and the interesting one is the third: a non-zero cost
that does not appear under ApplyEncounterResult means combat proper is drawing,
which nothing hooks, and the bracket residual goes positive for the first time.

docs/Z-tail-rng.md

@@ -180,3 +180,42 @@ cost this campaign has ever recorded — and the bracket total becomes `ProcessT
 
 This is the first genuinely falsifiable numeric claim this lane can make: every earlier one compared 0
 against 0.
+
+---
+
+## 7. P10, written with the encounter dialog on screen and unclicked
+
+The turn-54 End Turn on the Zuul long run stopped on an **Encounter at Gallandro**: the player's 5 ships
+(3 DE Colonizer, 2 DE Armor) against a **Von Neumann**, with the dialog offering Fight Manually / Auto
+Resolve / Fight Manually If Opponent Does / Retreat. Auto Resolve has not been clicked yet.
+
+This is the workload `sots-re/findings/control-flow/tail-rng-ledger.md` §8 says does not exist and lane J's
+`combat-resolver.md` asks for: **every encounter measured so far had `res->+0x4` set, so
+`ApplyEncounterResult` was a whole-function no-op and the combat resolver has never executed under any
+instrument this campaign has built.**
+
+**P10. Clicking Auto Resolve produces the first non-zero tail cost this campaign has recorded.**
+Specifically: `ApplyEncounterResult` records `res_no_battle = 0` for the first time; its measured `rng`
+delta is **greater than 0**; and `OnAllCombatDone_Tail`'s total equals that delta, because node-line decay
+is still 30-odd turns from firing and every other phase has measured 0 across 54 turns.
+
+On the size, following lane J's map of the three conditional sites: there is no node cannon here, so R1
+should not fire. A **Von Neumann is salvage** — R2 is one inlined `NextFloat` per back-engineering candidate
+per combatant with a non-zero salvage slot, and R3 one `NextInt` per successful R2 roll. So the expected
+cost is **small and odd-shaped: a handful of words, not a multiple of anything.** I am deliberately not
+naming a single number, because I have not read the resolver and lane J has: a range with a mechanism
+behind it is the honest form of this prediction.
+
+*Falsified by:*
+* **tail cost 0 with `res_no_battle = 0`** — then the resolver really has no draw on a plain battle path,
+  which would make lane J's "no unconditional draw" stronger than either of us expected, and would mean a
+  battle is free to a reimplementation;
+* **a large cost (tens or hundreds of words)** — then something in the battle path draws per ship or per
+  round, and the resolver's three sites are not the whole story;
+* **a non-zero cost that does NOT show up under `ApplyEncounterResult`** — then the draw happens in combat
+  proper (`RunCombatRound` / the combat server), which runs *between* `ProcessTurn` and the tail and is
+  hooked by nobody; the bracket residual would go positive for the first time and that is where it would
+  appear.
+
+The third case is the one to watch: it is the only way this workload can produce a **non-zero residual**,
+which every prediction so far has said should be 0 on a quiet turn.