fix(gift): 수령확인 시각을 초 단위로 정규화한다

src/main/kotlin/kr/co/vividnext/sodalive/v2/gift/application/GiftCommandService.kt

@@ -18,6 +18,7 @@ import org.springframework.data.repository.findByIdOrNull
 import org.springframework.stereotype.Service
 import org.springframework.transaction.annotation.Transactional
 import java.time.LocalDateTime
+import java.time.temporal.ChronoUnit
 
 data class GiftApplicationCommand(
     val recipientMemberId: Long,
@@ -297,7 +298,7 @@ class GiftCommandService(
             throw invalidRequest()
         }
         val delivery = deliveryRepository.findByGiftIdForUpdate(gift.id ?: throw invalidRequest()) ?: throw invalidRequest()
-        val deliveredAt = now()
+        val deliveredAt = now().truncatedTo(ChronoUnit.SECONDS)
 
         gift.status = GiftStatus.DELIVERED
         delivery.deliveredAt = deliveredAt