fix(gift): 관리자 취소 시각을 초 단위로 정규화한다

src/test/kotlin/kr/co/vividnext/sodalive/v2/gift/application/GiftAdminServiceTest.kt

@@ -25,6 +25,7 @@ import org.springframework.beans.factory.annotation.Autowired
 import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest
 import org.springframework.context.annotation.Import
 import java.time.LocalDateTime
+import javax.persistence.EntityManager
 
 @DataJpaTest(
     properties = [
@@ -39,7 +40,8 @@ class GiftAdminServiceTest @Autowired constructor(
     private val sizePriceRepository: GiftSizePriceRepository,
     private val giftRepository: GiftRepository,
     private val giftDeliveryRepository: GiftDeliveryRepository,
-    private val giftMailboxRepository: GiftMailboxRepository
+    private val giftMailboxRepository: GiftMailboxRepository,
+    private val entityManager: EntityManager
 ) {
     private val giftPushService = Mockito.mock(GiftPushService::class.java)
     private val canPaymentService = Mockito.mock(CanPaymentService::class.java)
@@ -332,6 +334,24 @@ class GiftAdminServiceTest @Autowired constructor(
         Mockito.verifyNoInteractions(giftPushService)
     }
 
+    @ParameterizedTest
+    @ValueSource(ints = [0, 123456789, 999999999])
+    @DisplayName("관리자 취소 시각은 나노초 입력에도 초 단위 저장값과 응답이 일치한다")
+    fun shouldPersistAndReturnSameSecondPrecisionCancellationTime(nanos: Int) {
+        val (gift, _) = saveGift(GiftStatus.RECEIVED)
+        val giftId = requireNotNull(gift.id)
+        val now = LocalDateTime.of(2026, 10, 22, 23, 59, 59, nanos)
+
+        val result = service.cancelGift(APPLICATION_NO, now)
+        entityManager.flush()
+        entityManager.clear()
+
+        val persisted = requireNotNull(giftDeliveryRepository.findByGiftId(giftId)?.canceledAt)
+        assertEquals(persisted, result.occurredAt)
+        assertEquals(LocalDateTime.of(2026, 10, 22, 23, 59, 59), persisted)
+        assertEquals(GiftStatus.CANCELED, giftRepository.findById(giftId).orElseThrow().status)
+    }
+
     @ParameterizedTest
     @EnumSource(value = GiftStatus::class, names = ["RECEIVED"], mode = EnumSource.Mode.EXCLUDE)
     @DisplayName("운영자는 접수가 아닌 모든 상태의 선물을 취소할 수 없다")