Review follow-up N: Misty's round-end procs fire in turn-based combat

DerivePlayerStats builds MistyHealProc / CrowdRevengeProc onto every turn-based
combatant, but stepRoundEnd had no counterpart to endOfRoundForSeat, so neither
was ever read. The buff (Misty's heal) was silently lost. The debuff (her
crowd's revenge) was an exploit: a player who declined Misty escaped it entirely
by fighting with !attack instead of letting the room auto-resolve -- no
discovery required, just press the button.

Hoisted both procs out of endOfRoundForSeat into shared helpers
(mistyCrowdRevenge, mistyHeal) and a seatEndOfRound hook that runs the pair in
the auto-resolve order. endOfRoundForSeat now calls the helpers; stepRoundEnd
calls seatEndOfRound per seat, after the poison tick so a heal can answer the
round's damage. A one-sided debuff-only hook would have been a second parallel
sibling of the kind deferred item D warns about, so the heal ships with it -- a
player-favourable discovery mechanic, consistent with the lift-trailers stance.

Both helpers short-circuit before st.randFloat() when their proc is unarmed, so
a character with no Misty history draws no dice: the sim corpus and
combat_characterization.golden do not move.

seatCombatResult now reads MistyHealed back off the misty_heal event (as
combat_pet_save always has), so combat_misty_clutch is reachable turn-based.
combat_sniper_kill stays unreachable -- Arina's proc is a pre-combat one-shot
with no round-end seam.

renderAllySeatEvent renders crowd_revenge as unattributed damage: an ally sees
the hit but not Misty's name, keeping the grudge the owner's own discovery.

Claude-Session: https://claude.ai/code/session_017mEwUmmS7aQTP2NQXj6rUa

internal/plugin/combat_session_build.go

@@ -208,21 +208,38 @@ func seatFightStartMods(sess *CombatSession, seat int, c *DnDCharacter) CombatMo
 // engine never builds a CombatResult — it persists a session and a shared event
 // log — so the close-out has to assemble one.
 //
-// SniperKilled and MistyHealed stay false because the turn engine has no Arina
-// or Misty proc to set them: those two live only in the auto-resolve engine.
+// MistyHealed is read back off the seat's event log rather than off a flag: the
+// turn engine's CombatResult is a scratch value it discards between steps, and
+// the log is the only thing that survives to the close-out. This is how
+// combat_pet_save has always been detected.
+//
+// SniperKilled stays false. Arina's proc is a pre-combat one-shot, not a
+// round-end effect, so seatEndOfRound does not carry it and the turn engine
+// still has no place to fire it — combat_sniper_kill remains unreachable from a
+// manual kill.
+//
 // NearDeath mirrors the auto-resolve engine's win threshold (below 15% of max);
 // its loss-side meaning is unused here, since the only hook that reads it gates
 // on PlayerWon.
 func seatCombatResult(sess *CombatSession, seat int) CombatResult {
 	hp, hpMax := sess.seatHP(seat), sess.seatHPMax(seat)
 	won := sess.Status == CombatStatusWon
+	events := eventsForSeat(sess.TurnLog, seat)
+	misty := false
+	for _, ev := range events {
+		if ev.Action == "misty_heal" {
+			misty = true
+			break
+		}
+	}
 	return CombatResult{
 		PlayerWon:   won,
-		Events:      eventsForSeat(sess.TurnLog, seat),
+		Events:      events,
 		PlayerEndHP: hp,
 		EnemyEndHP:  sess.EnemyHP,
 		TotalRounds: sess.Round,
 		NearDeath:   won && hp > 0 && float64(hp) < float64(max(1, hpMax))*0.15,
+		MistyHealed: misty,
 	}
 }