Support group battle preparation powers

game/combat-response-quote.ts

@@ -2,6 +2,7 @@ import { FACTIONS, type FactionId } from './catalog';
 import { voiceChoices } from './battle-cards';
 import { quoteEcazOccupyBattle, type EcazOccupyBattleProfile } from './ecaz-occupy-battle';
 import { validateNexusBorrowedVoice, type NexusBorrowedVoiceFrame } from './nexus-borrowed-voice';
+import { coalitionBattleBeneficiary, type CoalitionBattlePreparationContext } from './coalition-battle-preparation';
 
 export type CombatCheckKind =
   | 'kwisatz'
@@ -10,7 +11,7 @@ export type CombatCheckKind =
   | 'choamBattleAid';
 export type CombatResponseKind = CombatCheckKind | 'voice' | 'prescience';
 export type CombatCheck = { kind: CombatCheckKind; owner: string };
-export type CombatResponseInput = {
+export type CombatResponseInput = Omit<CoalitionBattlePreparationContext, 'players' | 'status' | 'advanced'> & {
   ecazOccupy?: EcazOccupyBattleProfile;
   status: string;
   phase: number;
@@ -21,6 +22,7 @@ export type CombatResponseInput = {
     id: string;
     faction: FactionId;
     ally?: string | null;
+    allySinceTurn?: number;
     specialKaramaUsed?: boolean;
   }[];
   battle: {
@@ -317,11 +319,7 @@ function calculate(
   requireCombat(owner, 'Combat preparation response has no owner.');
   // Match battlePreparation's existing provider selection, including its
   // one-way ally link. CHOAM's queue above independently requires mutual links.
-  const beneficiary = combatants.includes(owner.id)
-    ? owner.id
-    : owner.ally && combatants.includes(owner.ally)
-      ? owner.ally
-      : null;
+  const beneficiary = coalitionBattleBeneficiary(input, owner.id, b.attacker, b.defender);
   requireCombat(
     beneficiary,
     'Combat preparation owner has no combatant beneficiary.',
@@ -339,13 +337,7 @@ function calculate(
     // Voice has already advanced preparation to Prescience (or its finish).
     if (b.preparation !== undefined) {
       const atreides = input.players.find((p) => p.faction === 'atreides');
-      const recipient =
-        atreides &&
-        (combatants.includes(atreides.id)
-          ? atreides.id
-          : atreides.ally && combatants.includes(atreides.ally)
-            ? atreides.ally
-            : null);
+      const recipient = atreides && coalitionBattleBeneficiary(input, atreides.id, b.attacker, b.defender);
       requireCombat(
         record(b.preparation) &&
           b.preparation.kind === 'prescience' &&