Review fixes: align party enemy-HP scaling in the !fight entry path

The P8 diff scaled the enemy's max HP ×1.15 for parties at persist and
per-turn rebuild, but the !fight command's own template stayed unscaled:
the entry banner reported the pre-scale HP, and the opening-round settle
resolved the enemy against the wrong MaxHP ceiling (regen clamp, bloodied
threshold). Mirror the scalar for the banner and align the in-memory
template before the settle. Solo scales by 1.0, so it is untouched.

Also extract enemyActionPlan() so both combat engines share the one
load-bearing action-count computation instead of duplicating it.

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

internal/plugin/combat_cmd.go

@@ -101,7 +101,11 @@ func (p *AdventurePlugin) handleFightCmd(ctx MessageContext) error {
 	if refusal != "" {
 		return p.replyDM(ctx, refusal)
 	}
-	enemyHP := enemy.Stats.MaxHP
+	// The persisted session scales enemy HP for a party (solo scales by 1.0, so
+	// this is a no-op there); mirror it here so the entry banner and the opening
+	// round resolve against the same ceiling startPartyCombatSession persisted and
+	// the rebuilt rounds use.
+	enemyHP := scaledEnemyMaxHP(enemy.Stats.MaxHP, len(seats))
 
 	// Fight-start one-shot resources (Abjuration Arcane Ward, etc.) are seeded
 	// per seat onto the session and its participant rows, so they survive the
@@ -130,6 +134,11 @@ func (p *AdventurePlugin) handleFightCmd(ctx MessageContext) error {
 
 	if sess.IsParty() {
 		players := seatCombatants(seats)
+		// Align the in-memory template with the scaled HP persisted above, so the
+		// opening-round settle resolves the enemy against the same MaxHP the
+		// rebuilt rounds do (regen clamp, bloodied-ability threshold). The persist
+		// already happened off the unscaled value, so this does not double-scale.
+		enemy.Stats.MaxHP = enemyHP
 		// The enemy may have won initiative. Resolve everything the round owes
 		// before anyone is asked to act, so the opening block narrates the hit
 		// rather than showing its damage with no explanation.

internal/plugin/combat_engine_party.go

@@ -369,6 +369,22 @@ func scaledEnemyMaxHP(baseMaxHP, rosterSize int) int {
 	return int(float64(baseMaxHP) * partyEnemyHPScale(rosterSize))
 }
 
+// enemyActionPlan is the shared action budget both combat engines resolve an
+// enemy turn against: how many attack-actions the enemy takes, and whether the
+// first one reuses the round's already-picked target (and its already-rolled
+// procs). A cleave/lifesteal ability already spent the first action, so one fewer
+// follows and none of them reuse the initial target. Both engines call this so
+// the load-bearing count stays in lockstep even though their per-action bodies
+// differ.
+func enemyActionPlan(st *combatState, abilityDealtDamage bool) (count int, reuseFirst bool) {
+	count = enemyActionsThisRound(st)
+	reuseFirst = !abilityDealtDamage
+	if abilityDealtDamage {
+		count--
+	}
+	return count, reuseFirst
+}
+
 // enemyRoundSwings resolves the enemy's attacks for one round of the auto-resolve
 // engine. A solo roster takes exactly one swing at its single seat, reusing the
 // round's already-rolled target and pet procs, so its RNG stream and event log are
@@ -383,11 +399,7 @@ func scaledEnemyMaxHP(baseMaxHP, rosterSize int) int {
 func enemyRoundSwings(st *combatState, enemy *Combatant, phase *CombatPhase, seats []CombatResult,
 	target int, abilityDealtDamage, petWhiff, petDeflect, sporeMiss bool) bool {
 
-	swings := enemyActionsThisRound(st)
-	reuseFirst := !abilityDealtDamage
-	if abilityDealtDamage {
-		swings--
-	}
+	swings, reuseFirst := enemyActionPlan(st, abilityDealtDamage)
 	for k := 0; k < swings; k++ {
 		tgt := target
 		sw, sd, sp := petWhiff, petDeflect, sporeMiss

internal/plugin/combat_turn_engine.go

@@ -673,11 +673,7 @@ func (te *turnEngine) stepEnemyTurn() {
 	// drawn — so its event stream and RNG draws are unchanged. When the ability
 	// already dealt damage it was the first action, so one fewer follows; for solo
 	// that collapses to the old "the ability stood in for the attack" skip.
-	actions := enemyActionsThisRound(te.st)
-	reuseFirstTarget := !abilityDealtDamage
-	if abilityDealtDamage {
-		actions--
-	}
+	actions, reuseFirstTarget := enemyActionPlan(te.st, abilityDealtDamage)
 	for a := 0; a < actions; a++ {
 		if !(reuseFirstTarget && a == 0) {
 			tgt, alive := te.enemyTarget()