fix(channel-donation): 후원 목록 탈퇴 닉네임 접두사를 제거한다

src/test/kotlin/kr/co/vividnext/sodalive/explorer/profile/channelDonation/ChannelDonationServiceTest.kt

@@ -149,6 +149,54 @@ class ChannelDonationServiceTest {
         assertEquals(startDateTimeKst.plusMonths(1), endDateTimeKst)
     }
 
+    @Test
+    @DisplayName("탈퇴 회원 닉네임 접두사는 목록 응답에서 제거된다")
+    fun shouldRemoveDeletedPrefixFromNicknameInDonationList() {
+        // given: 탈퇴 접두사가 포함된 후원자 닉네임 데이터를 준비한다.
+        val creator = createMember(id = 1L, role = MemberRole.CREATOR, nickname = "creator")
+        val viewer = createMember(id = 2L, role = MemberRole.USER, nickname = "viewer")
+        val withdrawnMember = createMember(id = 3L, role = MemberRole.USER, nickname = "deleted_withdrawn")
+        val message = ChannelDonationMessage(can = 3, isSecret = false, additionalMessage = null)
+        message.id = 1002L
+        message.member = withdrawnMember
+        message.creator = creator
+        message.createdAt = LocalDateTime.of(2026, 2, 20, 12, 0, 0)
+
+        // given: 목록 조회 repository 응답을 설정한다.
+        Mockito.`when`(memberRepository.findCreatorByIdOrNull(creator.id!!)).thenReturn(creator)
+        Mockito.`when`(
+            channelDonationMessageRepository.getChannelDonationMessageTotalCount(
+                Mockito.eq(creator.id!!),
+                Mockito.eq(viewer.id!!),
+                Mockito.eq(false),
+                anyLocalDateTime(),
+                anyLocalDateTime()
+            )
+        ).thenReturn(1)
+        Mockito.`when`(
+            channelDonationMessageRepository.getChannelDonationMessageList(
+                Mockito.eq(creator.id!!),
+                Mockito.eq(viewer.id!!),
+                Mockito.eq(false),
+                Mockito.eq(0L),
+                Mockito.eq(5L),
+                anyLocalDateTime(),
+                anyLocalDateTime()
+            )
+        ).thenReturn(listOf(message))
+
+        // when: 채널 후원 목록 조회를 실행한다.
+        val result = service.getChannelDonationList(
+            creatorId = creator.id!!,
+            member = viewer,
+            offset = 0,
+            limit = 5
+        )
+
+        // then: 응답 닉네임에서 deleted_ 접두사가 제거되어야 한다.
+        assertEquals("withdrawn", result.items[0].nickname)
+    }
+
     @Test
     @DisplayName("후원 캔 수는 천 단위 콤마가 포함된 메시지로 포맷된다")
     fun shouldFormatCanWithCommaInDonationMessage() {