홈 크리에이터 랭킹 팔로우 조회 최적화

홈 API의 크리에이터 랭킹 응답에서 팔로우 여부를 일괄 조회로 계산한다.

src/main/kotlin/kr/co/vividnext/sodalive/explorer/ExplorerQueryRepository.kt

@@ -637,6 +637,23 @@ class ExplorerQueryRepository(
             .fetchOne() ?: false
     }
 
+    fun getFollowedCreatorIds(creatorIds: List<Long>, memberId: Long): Set<Long> {
+        if (creatorIds.isEmpty()) {
+            return emptySet()
+        }
+
+        return queryFactory
+            .select(creatorFollowing.creator.id)
+            .from(creatorFollowing)
+            .where(
+                creatorFollowing.isActive.isTrue
+                    .and(creatorFollowing.creator.id.`in`(creatorIds))
+                    .and(creatorFollowing.member.id.eq(memberId))
+            )
+            .fetch()
+            .toSet()
+    }
+
     fun getCreatorCheers(cheersId: Long): CreatorCheers? {
         return queryFactory
             .selectFrom(creatorCheers)