feat: apply feedback updates and streamline online delivery

src/lib/engine/event-optimization.test.ts

@@ -1,7 +1,7 @@
 import test from 'node:test';
 import assert from 'node:assert/strict';
 import { events } from '../data/events.ts';
-import { activeEventAt, eventBonusBreakdown, eventChallengeSongScoreBonusPercent, eventPointIndex } from './event-optimization.ts';
+import { activeEventAt, eventBonusBreakdown, eventChallengeSongScoreBonusPercent, eventOptimizationCardEligible, eventPointIndex } from './event-optimization.ts';
 
 const currentEvent = events[0];
 
@@ -11,6 +11,15 @@ test('이벤트 기간 안에서만 진행 중 이벤트를 반환한다', () =>
   assert.equal(activeEventAt(events, Date.parse('2026-09-06T11:00:00.000Z')), null);
 });
 
+test('이벤트 최적화는 모든 4·5성과 보너스 멤버의 저등급 카드를 후보로 사용한다', () => {
+  const bonusCharacters = new Set(['bonus']);
+
+  assert.equal(eventOptimizationCardEligible({ id: 'five', characterId: 'other', rarity: 5 }, bonusCharacters), true);
+  assert.equal(eventOptimizationCardEligible({ id: 'four', characterId: 'other', rarity: 4 }, bonusCharacters), true);
+  assert.equal(eventOptimizationCardEligible({ id: 'bonus-three', characterId: 'bonus', rarity: 3 }, bonusCharacters), true);
+  assert.equal(eventOptimizationCardEligible({ id: 'regular-three', characterId: 'other', rarity: 3 }, bonusCharacters), false);
+});
+
 test('편성·신규 카드·개화 보너스를 카드별로 합산한다', () => {
   const cards = [
     { id: currentEvent.featuredCardIds[0], characterId: currentEvent.bonusCharacterIds[0], rarity: 5 },