diff --git a/docs/convention/composable-callback-defaults.md b/docs/convention/composable-callback-defaults.md
new file mode 100644
index 0000000000..41cf59c77f
--- /dev/null
+++ b/docs/convention/composable-callback-defaults.md
@@ -0,0 +1,73 @@
+# 컴포저블 콜백 디폴트 규칙
+
+**컴포저블의 `on*` 콜백 파라미터에 no-op 디폴트(`onXxx: (...) -> Unit = {}`)를 두지 않는다.** 선택적 상호작용은 디폴트가 아니라 타입(nullable 핸들러·오버로드)으로 모델링한다.
+
+`app` · `feature/*` 모듈의 `src/main` 에 적용하고, `konsist` 의 `NoOpCallbackDefaultKonsistTest` 가 강제한다 (#1388).
+
+## 왜 금지인가
+
+no-op 디폴트는 **배선을 빠뜨려도 컴파일이 통과**하게 만든다. 화면은 그려지고, 버튼도 눌리는데, 아무 일도 일어나지 않는다 — 실패가 조용해서 QA 나 사용자 신고로만 드러난다.
+
+실사고 전례가 반복됐다:
+
+- #582 · #618 · #722 — mindrecord 미배선 실사고. 콜백을 넘기지 않은 채 화면이 출고됐다.
+- #777 — 137건 전수 대조로 실결함을 적출했지만, **디폴트 자체가 남아 있어 같은 부류가 재발할 통로가 열려 있었다.** 신설 코드가 패턴을 답습하는 것도 확인됐다(PR #1336 의 `onVideoClick`).
+- #778 (open) — `TimeLetterWriteScreen.onTextStyleClick` 이 지금도 미배선 의심으로 추적 중이다.
+
+디폴트가 없으면 같은 실수가 **컴파일 에러**로 드러난다. 폴백보다 값 명시·타입으로 강제한다는 #934 방침과 같은 방향이다.
+
+## 처분 기준
+
+### 화면 컴포저블 — 디폴트 전면 제거
+
+실호출부가 NavGraph 한 곳인 화면 컴포저블은 콜백을 전부 required 로 한다. 프리뷰 · screenshotTest · unit test 는 `{}` 를 **명시**한다 (#602 전례).
+
+```kotlin
+// Before
+fun GalleryDetailScreen(
+    onBackClick: () -> Unit,
+    onEditClick: () -> Unit = {},      // 배선 누락이 조용히 no-op
+)
+
+// After
+fun GalleryDetailScreen(
+    onBackClick: () -> Unit,
+    onEditClick: () -> Unit,           // 누락 = 컴파일 에러
+)
+
+// Preview / screenshotTest
+GalleryDetailScreen(onBackClick = {}, onEditClick = {})
+```
+
+`{}` 명시는 디폴트와 렌더링이 동일하므로 스크린샷 baseline 이 유지된다. reference PNG 재생성이 필요한 처분이라면 그 처분이 틀린 것이다(골든 정본은 CI 컨테이너 — `docs/testing` 참고).
+
+### 다중 호출부 리프 컴포넌트 — 건별 판정
+
+- **전 호출부가 실값을 넘긴다** → 디폴트만 제거한다. 선택성이 실재하지 않았던 것이다.
+- **상호작용이 진짜 선택적이다** → `= {}` 로 "눌러도 아무 일 없는 버튼"을 그리는 대신, 상호작용 UI 자체를 접는다:
+
+```kotlin
+// nullable 핸들러 + UI 숨김 (EditDropdownMenu, #1388)
+fun EditDropdownMenu(
+    onDeleteClick: () -> Unit,
+    onEditClick: (() -> Unit)?,        // null = 편집 항목을 그리지 않는다
+) {
+    if (onEditClick != null) {
+        CustomDropdownItem(text = "수정", onClick = onEditClick)
+    }
+}
+```
+
+nullable 핸들러에도 **`= null` 디폴트를 두지 않는다** — 호출부가 "핸들러 있음 / 의도적으로 없음" 을 매번 명시해야 미배선과 의도적 생략이 구분된다. `showEditItem: Boolean` 같은 플래그 + no-op 콜백 짝은 nullable 핸들러 하나로 합친다(플래그와 콜백이 어긋나는 상태를 타입에서 제거).
+
+상호작용 조합이 많아 nullable 이 지저분해지면 오버로드 분리(상호작용 있는 시그니처 / 없는 시그니처)를 쓴다.
+
+### 콜백 홀더 클래스도 같다
+
+`ReceiverHomeActions` 처럼 콜백을 프로퍼티로 묶은 클래스의 `val onXxx: () -> Unit = {}` 도 같은 방식으로 미배선을 숨긴다. 가드가 클래스 주 생성자까지 본다.
+
+## 강제 수단
+
+`konsist/src/test/kotlin/com/afternote/konsist/NoOpCallbackDefaultKonsistTest.kt` 가 app · feature `src/main` 의 `@Composable` 함수 파라미터와 클래스 주 생성자 파라미터를 스캔해, `on`+대문자 이름에 no-op 람다 기본값(`{}` · `{ }` · `{ _ -> }`)이 있으면 실패시킨다.
+
+가드 도입 시점의 잔여 파일은 테스트 안 `LEGACY_NO_OP_DEFAULT_FILES` 에 있다. 목록의 파일은 위반이 있어도 없어도 통과한다(관대 판정 — 청소 PR 과 목록 갱신 PR 의 머지 순서가 develop 을 red 로 만들지 않게). 모듈 담당별 후속 PR(#1388 의 자식 이슈)이 청소하면서 목록에서 빼면 되고, 빼는 걸 잊으면 「해소된 항목은 경고로 알린다」 테스트가 CI 로그에 경고를 남긴다.
diff --git a/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/detail/GalleryDetailScreen.kt b/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/detail/GalleryDetailScreen.kt
index bad488135d..f23e1b369b 100644
--- a/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/detail/GalleryDetailScreen.kt
+++ b/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/detail/GalleryDetailScreen.kt
@@ -60,8 +60,8 @@ fun GalleryDetailScreen(
     content: GalleryDetailContent = GalleryDetailContent(),
     snackbarHostState: SnackbarHostState = remember { SnackbarHostState() },
     isEditable: Boolean = true,
-    onEditClick: () -> Unit = {},
-    onDeleteConfirm: () -> Unit = {},
+    onEditClick: () -> Unit,
+    onDeleteConfirm: () -> Unit,
     state: AfternoteDetailState = rememberAfternoteDetailState(),
 ) {
     if (isEditable && state.showDeleteDialog) {
diff --git a/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/detail/account/AccountDetailScreen.kt b/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/detail/account/AccountDetailScreen.kt
index 5506d1a497..0123de84e2 100644
--- a/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/detail/account/AccountDetailScreen.kt
+++ b/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/detail/account/AccountDetailScreen.kt
@@ -141,8 +141,8 @@ fun AccountDetailScreen(
     content: AccountDetailContent = AccountDetailContent(),
     snackbarHostState: SnackbarHostState = remember { SnackbarHostState() },
     isEditable: Boolean = true,
-    onEditClick: () -> Unit = {},
-    onDeleteConfirm: () -> Unit = {},
+    onEditClick: () -> Unit,
+    onDeleteConfirm: () -> Unit,
     state: AfternoteDetailState = rememberAfternoteDetailState(),
 ) {
     if (isEditable && state.showDeleteDialog) {
diff --git a/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/editor/AfternoteEditorContent.kt b/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/editor/AfternoteEditorContent.kt
index 2400a3139c..4a10aac705 100644
--- a/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/editor/AfternoteEditorContent.kt
+++ b/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/editor/AfternoteEditorContent.kt
@@ -277,7 +277,7 @@ internal fun AfternoteTypeContent(
     onPhotoAddClick: () -> Unit,
     onVideoAddClick: () -> Unit,
     onThumbnailBytesReady: (ByteArray?) -> Unit,
-    onThumbnailExtractionFailed: (Throwable) -> Unit = {},
+    onThumbnailExtractionFailed: (Throwable) -> Unit,
 ) {
     when (form.selectedType) {
         AfternoteType.MEMORIAL -> {
diff --git a/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/MemorialPhotoUpload.kt b/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/MemorialPhotoUpload.kt
index cf6bd3c502..bc105afc72 100644
--- a/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/MemorialPhotoUpload.kt
+++ b/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/MemorialPhotoUpload.kt
@@ -19,7 +19,7 @@ fun MemorialPhotoUpload(
     modifier: Modifier = Modifier,
     label: String? = null,
     displayImageUri: String? = null,
-    onAddPhotoClick: () -> Unit = {},
+    onAddPhotoClick: () -> Unit,
 ) {
     val labelText = label ?: stringResource(R.string.afternote_editor_memorial_photo_label)
     Column(
diff --git a/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/MemorialVideoUpload.kt b/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/MemorialVideoUpload.kt
index a9ed303693..d898070e36 100644
--- a/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/MemorialVideoUpload.kt
+++ b/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/MemorialVideoUpload.kt
@@ -71,8 +71,8 @@ fun MemorialVideoUpload(
     videoUrl: String? = null,
     thumbnailUrl: String? = null,
     onAddVideoClick: () -> Unit,
-    onThumbnailBytesReady: (ByteArray?) -> Unit = {},
-    onThumbnailExtractionFailed: (Throwable) -> Unit = {},
+    onThumbnailBytesReady: (ByteArray?) -> Unit,
+    onThumbnailExtractionFailed: (Throwable) -> Unit,
     ioDispatcher: CoroutineDispatcher = Dispatchers.IO,
 ) {
     val hasVideo = !videoUrl.isNullOrBlank()
diff --git a/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/playlist/MemorialPlaylistEntry.kt b/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/playlist/MemorialPlaylistEntry.kt
index 8d270b44b3..20109bd0d8 100644
--- a/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/playlist/MemorialPlaylistEntry.kt
+++ b/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/playlist/MemorialPlaylistEntry.kt
@@ -64,10 +64,10 @@ import com.afternote.feature.afternote.presentation.shared.model.PlaylistSongDis
 fun MemorialPlaylistEntry(
     songs: List<Song>,
     modifier: Modifier = Modifier,
-    onBackClick: () -> Unit = {},
-    onNavigateToAddSongScreen: () -> Unit = {},
-    onClearAllSongs: () -> Unit = {},
-    onRemoveSongs: (Set<String>) -> Unit = {},
+    onBackClick: () -> Unit,
+    onNavigateToAddSongScreen: () -> Unit,
+    onClearAllSongs: () -> Unit,
+    onRemoveSongs: (Set<String>) -> Unit,
     initialEditMode: Boolean = false,
     initialSelectedSongKeys: Set<String> = emptySet(),
 ) {
diff --git a/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/editor/processing/ProcessingMethodCheckbox.kt b/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/editor/processing/ProcessingMethodCheckbox.kt
index de00730558..81492ef1c9 100644
--- a/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/editor/processing/ProcessingMethodCheckbox.kt
+++ b/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/editor/processing/ProcessingMethodCheckbox.kt
@@ -55,11 +55,11 @@ fun ProcessingMethodCheckbox(
     item: ProcessingMethodItem,
     expanded: Boolean = false,
     isEditing: Boolean = false,
-    onMoreClick: () -> Unit = {},
-    onDismissDropdown: () -> Unit = {},
-    onEditClick: () -> Unit = {},
-    onDeleteClick: () -> Unit = {},
-    onEditConfirmed: (String) -> Unit = {},
+    onMoreClick: () -> Unit,
+    onDismissDropdown: () -> Unit,
+    onEditClick: () -> Unit,
+    onDeleteClick: () -> Unit,
+    onEditConfirmed: (String) -> Unit,
 ) {
     Row(
         modifier = modifier.fillMaxWidth(),
diff --git a/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/editor/receiver/AfternoteEditorReceiverList.kt b/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/editor/receiver/AfternoteEditorReceiverList.kt
index 8482e932ef..618d309bd1 100644
--- a/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/editor/receiver/AfternoteEditorReceiverList.kt
+++ b/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/author/editor/receiver/AfternoteEditorReceiverList.kt
@@ -72,7 +72,6 @@ fun AfternoteEditorReceiverList(
                 onDismissDropdown = {
                     state.expandedStates[receiver.id] = false
                 },
-                showEditItem = false,
                 onDeleteClick = { onItemDeleteClick(receiver.id) },
             )
         }
@@ -101,10 +100,9 @@ private fun AfternoteEditorReceiverItem(
     modifier: Modifier = Modifier,
     receiver: AfternoteEditorReceiver,
     expanded: Boolean = false,
-    onMoreClick: () -> Unit = {},
-    onDismissDropdown: () -> Unit = {},
-    showEditItem: Boolean = true,
-    onDeleteClick: () -> Unit = {},
+    onMoreClick: () -> Unit,
+    onDismissDropdown: () -> Unit,
+    onDeleteClick: () -> Unit,
 ) {
     Row(
         modifier =
@@ -145,7 +143,8 @@ private fun AfternoteEditorReceiverItem(
                 expanded = expanded,
                 onDismissRequest = onDismissDropdown,
                 onDeleteClick = onDeleteClick,
-                showEditItem = showEditItem,
+                // 수신자 행 메뉴엔 편집이 없다 — null 이 편집 항목 자체를 숨긴다.
+                onEditClick = null,
             )
         }
     }
diff --git a/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/shared/body/infinite/content/list/item/ContentListItem.kt b/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/shared/body/infinite/content/list/item/ContentListItem.kt
index 8710125e30..7702fdc806 100644
--- a/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/shared/body/infinite/content/list/item/ContentListItem.kt
+++ b/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/shared/body/infinite/content/list/item/ContentListItem.kt
@@ -33,7 +33,7 @@ import com.afternote.feature.afternote.presentation.R
 fun AfternoteListItem(
     uiModel: ListItemUiModel,
     modifier: Modifier = Modifier,
-    onClick: () -> Unit = {},
+    onClick: () -> Unit,
 ) {
     Row(
         modifier =
diff --git a/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/shared/detail/EditDropdownMenu.kt b/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/shared/detail/EditDropdownMenu.kt
index e1cf46dc82..93f4cc7d88 100644
--- a/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/shared/detail/EditDropdownMenu.kt
+++ b/feature/afternote/presentation/src/main/kotlin/com/afternote/feature/afternote/presentation/shared/detail/EditDropdownMenu.kt
@@ -36,15 +36,18 @@ import androidx.compose.ui.window.Popup as ComposePopup
  * Material3 `DropdownMenu` 과 달리 `androidx.compose.ui.window.Popup` 기반이라
  * 등장 페이드·스케일 애니메이션은 없다. 필요하면 메뉴 `Column` 을
  * `androidx.compose.animation.AnimatedVisibility` 로 감싸면 된다.
+ *
+ * @param onEditClick 편집 항목 클릭 콜백. **null 이면 편집 항목 자체를 그리지 않는다** — 편집이
+ *   없는 메뉴(수신자 행)와 "핸들러를 안 넘겨 죽은 편집 버튼이 그려지는" 미배선을 타입으로 구분하기
+ *   위해 `showEditItem` 플래그 + no-op 디폴트 대신 nullable 핸들러 하나로 모델링한다 (#1388).
  */
 @Composable
 fun EditDropdownMenu(
     expanded: Boolean,
     onDismissRequest: () -> Unit,
     onDeleteClick: () -> Unit,
+    onEditClick: (() -> Unit)?,
     modifier: Modifier = Modifier,
-    onEditClick: () -> Unit = {},
-    showEditItem: Boolean = true,
     popupPositionProvider: PopupPositionProvider = rememberFixedRightPopupPositionProvider(),
 ) {
     if (!expanded) return
@@ -55,11 +58,13 @@ fun EditDropdownMenu(
         properties = PopupProperties(focusable = true),
     ) {
         EditDropdownMenuItems(
-            showEditItem = showEditItem,
-            onEditClick = {
-                onDismissRequest()
-                onEditClick()
-            },
+            onEditClick =
+                onEditClick?.let { onEdit ->
+                    {
+                        onDismissRequest()
+                        onEdit()
+                    }
+                },
             onDeleteClick = {
                 onDismissRequest()
                 onDeleteClick()
@@ -76,8 +81,7 @@ fun EditDropdownMenu(
  */
 @Composable
 private fun EditDropdownMenuItems(
-    showEditItem: Boolean,
-    onEditClick: () -> Unit,
+    onEditClick: (() -> Unit)?,
     onDeleteClick: () -> Unit,
     modifier: Modifier = Modifier,
 ) {
@@ -92,7 +96,7 @@ private fun EditDropdownMenuItems(
                 ).background(AfternoteDesign.colors.white)
                 .width(IntrinsicSize.Max),
     ) {
-        if (showEditItem) {
+        if (onEditClick != null) {
             CustomDropdownItem(
                 text = stringResource(R.string.feature_afternote_menu_edit),
                 onClick = onEditClick,
diff --git a/feature/afternote/presentation/src/screenshotTest/kotlin/com/afternote/feature/afternote/presentation/author/detail/GalleryDetailScreenScreenshotTest.kt b/feature/afternote/presentation/src/screenshotTest/kotlin/com/afternote/feature/afternote/presentation/author/detail/GalleryDetailScreenScreenshotTest.kt
index 6cf74d9c84..a59565ea03 100644
--- a/feature/afternote/presentation/src/screenshotTest/kotlin/com/afternote/feature/afternote/presentation/author/detail/GalleryDetailScreenScreenshotTest.kt
+++ b/feature/afternote/presentation/src/screenshotTest/kotlin/com/afternote/feature/afternote/presentation/author/detail/GalleryDetailScreenScreenshotTest.kt
@@ -12,6 +12,8 @@ internal fun galleryDetailScreenScreenshot() {
     AfternoteTheme {
         GalleryDetailScreen(
             onBackClick = {},
+            onEditClick = {},
+            onDeleteConfirm = {},
             content =
                 GalleryDetailContent(
                     serviceName = "직접 입력한 갤러리 서비스",
diff --git a/feature/afternote/presentation/src/screenshotTest/kotlin/com/afternote/feature/afternote/presentation/author/detail/account/AccountDetailScreenScreenshotTest.kt b/feature/afternote/presentation/src/screenshotTest/kotlin/com/afternote/feature/afternote/presentation/author/detail/account/AccountDetailScreenScreenshotTest.kt
index f6e63085d7..56ed55f71e 100644
--- a/feature/afternote/presentation/src/screenshotTest/kotlin/com/afternote/feature/afternote/presentation/author/detail/account/AccountDetailScreenScreenshotTest.kt
+++ b/feature/afternote/presentation/src/screenshotTest/kotlin/com/afternote/feature/afternote/presentation/author/detail/account/AccountDetailScreenScreenshotTest.kt
@@ -13,6 +13,8 @@ internal fun accountDetailScreenScreenshot() {
     AfternoteTheme {
         AccountDetailScreen(
             onBackClick = {},
+            onEditClick = {},
+            onDeleteConfirm = {},
             content =
                 AccountDetailContent(
                     serviceName = "직접 입력한 소셜 서비스",
@@ -30,6 +32,8 @@ internal fun accountDetailBusinessFallbackScreenshot() {
     AfternoteTheme {
         AccountDetailScreen(
             onBackClick = {},
+            onEditClick = {},
+            onDeleteConfirm = {},
             content =
                 AccountDetailContent(
                     serviceName = "직접 입력한 비즈니스 서비스",
diff --git a/feature/afternote/presentation/src/screenshotTest/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/MemorialPhotoUploadScreenshotTest.kt b/feature/afternote/presentation/src/screenshotTest/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/MemorialPhotoUploadScreenshotTest.kt
index cc0b6990d1..d8781f044a 100644
--- a/feature/afternote/presentation/src/screenshotTest/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/MemorialPhotoUploadScreenshotTest.kt
+++ b/feature/afternote/presentation/src/screenshotTest/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/MemorialPhotoUploadScreenshotTest.kt
@@ -17,6 +17,7 @@ internal fun memorialPhotoUploadEmptyScreenshot() {
             modifier = Modifier.padding(16.dp),
             label = "추모 사진",
             displayImageUri = null,
+            onAddPhotoClick = {},
         )
     }
 }
diff --git a/feature/afternote/presentation/src/screenshotTest/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/MemorialVideoUploadScreenshotTest.kt b/feature/afternote/presentation/src/screenshotTest/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/MemorialVideoUploadScreenshotTest.kt
index f86c866350..a8a356d324 100644
--- a/feature/afternote/presentation/src/screenshotTest/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/MemorialVideoUploadScreenshotTest.kt
+++ b/feature/afternote/presentation/src/screenshotTest/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/MemorialVideoUploadScreenshotTest.kt
@@ -19,6 +19,8 @@ internal fun memorialVideoUploadEmptyScreenshot() {
             videoUrl = null,
             thumbnailUrl = null,
             onAddVideoClick = {},
+            onThumbnailBytesReady = {},
+            onThumbnailExtractionFailed = {},
         )
     }
 }
diff --git a/feature/afternote/presentation/src/screenshotTest/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/playlist/MemorialPlaylistEntryScreenshotTest.kt b/feature/afternote/presentation/src/screenshotTest/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/playlist/MemorialPlaylistEntryScreenshotTest.kt
index 54aaf306b3..272d3ddfe9 100644
--- a/feature/afternote/presentation/src/screenshotTest/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/playlist/MemorialPlaylistEntryScreenshotTest.kt
+++ b/feature/afternote/presentation/src/screenshotTest/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/playlist/MemorialPlaylistEntryScreenshotTest.kt
@@ -26,7 +26,13 @@ private fun screenshotSongs(): List<Song> =
 @Composable
 internal fun memorialPlaylistEntryEmptyScreenshot() {
     AfternoteTheme {
-        MemorialPlaylistEntry(songs = emptyList())
+        MemorialPlaylistEntry(
+            songs = emptyList(),
+            onBackClick = {},
+            onNavigateToAddSongScreen = {},
+            onClearAllSongs = {},
+            onRemoveSongs = {},
+        )
     }
 }
 
@@ -35,7 +41,13 @@ internal fun memorialPlaylistEntryEmptyScreenshot() {
 @Composable
 internal fun memorialPlaylistEntryWithSongsScreenshot() {
     AfternoteTheme {
-        MemorialPlaylistEntry(songs = screenshotSongs())
+        MemorialPlaylistEntry(
+            songs = screenshotSongs(),
+            onBackClick = {},
+            onNavigateToAddSongScreen = {},
+            onClearAllSongs = {},
+            onRemoveSongs = {},
+        )
     }
 }
 
@@ -46,6 +58,10 @@ internal fun memorialPlaylistEntryEditModeScreenshot() {
     AfternoteTheme {
         MemorialPlaylistEntry(
             songs = screenshotSongs(),
+            onBackClick = {},
+            onNavigateToAddSongScreen = {},
+            onClearAllSongs = {},
+            onRemoveSongs = {},
             initialEditMode = true,
         )
     }
@@ -58,6 +74,10 @@ internal fun memorialPlaylistEntryEditModeSelectionScreenshot() {
     AfternoteTheme {
         MemorialPlaylistEntry(
             songs = screenshotSongs(),
+            onBackClick = {},
+            onNavigateToAddSongScreen = {},
+            onClearAllSongs = {},
+            onRemoveSongs = {},
             initialEditMode = true,
             initialSelectedSongKeys = setOf("screenshot:1"),
         )
diff --git a/feature/afternote/presentation/src/screenshotTest/kotlin/com/afternote/feature/afternote/presentation/author/editor/processing/ProcessingMethodCheckboxScreenshotTest.kt b/feature/afternote/presentation/src/screenshotTest/kotlin/com/afternote/feature/afternote/presentation/author/editor/processing/ProcessingMethodCheckboxScreenshotTest.kt
index 96df6e7392..b387f57abb 100644
--- a/feature/afternote/presentation/src/screenshotTest/kotlin/com/afternote/feature/afternote/presentation/author/editor/processing/ProcessingMethodCheckboxScreenshotTest.kt
+++ b/feature/afternote/presentation/src/screenshotTest/kotlin/com/afternote/feature/afternote/presentation/author/editor/processing/ProcessingMethodCheckboxScreenshotTest.kt
@@ -17,6 +17,11 @@ internal fun processingMethodCheckboxScreenshot() {
         ProcessingMethodCheckbox(
             item = ProcessingMethodItem(localId = 1, text = "보관"),
             modifier = Modifier.padding(16.dp),
+            onMoreClick = {},
+            onDismissDropdown = {},
+            onEditClick = {},
+            onDeleteClick = {},
+            onEditConfirmed = {},
         )
     }
 }
diff --git a/feature/afternote/presentation/src/test/kotlin/com/afternote/feature/afternote/presentation/author/AfternoteAuthorExtendedTest.kt b/feature/afternote/presentation/src/test/kotlin/com/afternote/feature/afternote/presentation/author/AfternoteAuthorExtendedTest.kt
index 54c40c95e5..76e60ad496 100644
--- a/feature/afternote/presentation/src/test/kotlin/com/afternote/feature/afternote/presentation/author/AfternoteAuthorExtendedTest.kt
+++ b/feature/afternote/presentation/src/test/kotlin/com/afternote/feature/afternote/presentation/author/AfternoteAuthorExtendedTest.kt
@@ -334,6 +334,7 @@ private fun AuthorDetailForEdit(
                 onBackClick = {},
                 content = account.content,
                 onEditClick = { onEdit(state.detailId.toString()) },
+                onDeleteConfirm = {},
             )
         }
     }
@@ -470,6 +471,7 @@ private fun AuthorDetailForDelete(
                 onBackClick = {},
                 content = account.content,
                 snackbarHostState = snackbarHostState,
+                onEditClick = {},
                 onDeleteConfirm = { viewModel.deleteAfternote(state.detailId) },
             )
         }
diff --git a/feature/afternote/presentation/src/test/kotlin/com/afternote/feature/afternote/presentation/author/editor/EditorTouchTargetTest.kt b/feature/afternote/presentation/src/test/kotlin/com/afternote/feature/afternote/presentation/author/editor/EditorTouchTargetTest.kt
index 5d3712d631..916acdd75e 100644
--- a/feature/afternote/presentation/src/test/kotlin/com/afternote/feature/afternote/presentation/author/editor/EditorTouchTargetTest.kt
+++ b/feature/afternote/presentation/src/test/kotlin/com/afternote/feature/afternote/presentation/author/editor/EditorTouchTargetTest.kt
@@ -115,6 +115,10 @@ class EditorTouchTargetTest {
                     ProcessingMethodCheckbox(
                         item = ProcessingMethodItem(1, "Method"),
                         onMoreClick = { processingMoreClicks++ },
+                        onDismissDropdown = {},
+                        onEditClick = {},
+                        onDeleteClick = {},
+                        onEditConfirmed = {},
                     )
                     AfternoteEditorReceiverList(
                         afternoteEditReceivers =
diff --git a/feature/afternote/presentation/src/test/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/MemorialVideoUploadInteractionTest.kt b/feature/afternote/presentation/src/test/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/MemorialVideoUploadInteractionTest.kt
index 0b75f7e177..b961da628a 100644
--- a/feature/afternote/presentation/src/test/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/MemorialVideoUploadInteractionTest.kt
+++ b/feature/afternote/presentation/src/test/kotlin/com/afternote/feature/afternote/presentation/author/editor/memorial/MemorialVideoUploadInteractionTest.kt
@@ -25,7 +25,11 @@ class MemorialVideoUploadInteractionTest {
         var addClicks = 0
         composeRule.setContent {
             AfternoteTheme {
-                MemorialVideoUpload(onAddVideoClick = { addClicks += 1 })
+                MemorialVideoUpload(
+                    onAddVideoClick = { addClicks += 1 },
+                    onThumbnailBytesReady = {},
+                    onThumbnailExtractionFailed = {},
+                )
             }
         }
 
diff --git a/konsist/build.gradle.kts b/konsist/build.gradle.kts
index c1a06d05d9..55ff2b1222 100644
--- a/konsist/build.gradle.kts
+++ b/konsist/build.gradle.kts
@@ -1,7 +1,21 @@
 plugins {
     id("java-library")
     alias(libs.plugins.jetbrains.kotlin.jvm)
+    // build-logic 이 이미 클래스패스에 올려 둔 플러그인이라 버전을 다시 선언하면 충돌한다.
+    id("org.jlleitschuh.gradle.ktlint")
 }
+
+// 이 모듈은 convention plugin(afternote.jvm.library) 대신 java-library 를 직접 쓰느라 ktlint 만
+// 빠져 있었다. resolve-pr-impact.mjs 는 «.kt 가 바뀐 모듈» 마다 `<모듈>:ktlintCheck` 를 고르므로
+// (PR #1279 이후), 태스크가 없으면 konsist 소스를 건드리는 PR 의 Ktlint job 이 태스크 선택 단계에서
+// 죽는다. build-logic 과 같은 방식으로 플러그인만 직접 적용한다.
+ktlint {
+    version.set(libs.versions.ktlint)
+    filter {
+        exclude { it.file.path.contains("build/") }
+    }
+}
+
 java {
     sourceCompatibility = JavaVersion.VERSION_11
     targetCompatibility = JavaVersion.VERSION_11
diff --git a/konsist/src/test/kotlin/com/afternote/konsist/NoOpCallbackDefaultKonsistTest.kt b/konsist/src/test/kotlin/com/afternote/konsist/NoOpCallbackDefaultKonsistTest.kt
new file mode 100644
index 0000000000..3416c64905
--- /dev/null
+++ b/konsist/src/test/kotlin/com/afternote/konsist/NoOpCallbackDefaultKonsistTest.kt
@@ -0,0 +1,195 @@
+package com.afternote.konsist
+
+import com.lemonappdev.konsist.api.Konsist
+import com.lemonappdev.konsist.api.declaration.KoFileDeclaration
+import com.lemonappdev.konsist.api.declaration.KoParameterDeclaration
+import org.junit.Test
+
+/**
+ * 컴포저블 no-op 콜백 디폴트 회귀 가드 (#1388).
+ *
+ * `onXxx: (...) -> Unit = {}` 는 배선을 빠뜨려도 컴파일이 통과해 조용히 no-op 이 된다 —
+ * "눌러도 아무 일 없는 버튼" 실사고가 #582 · #618 · #722 · #777 로 반복된 패턴이다.
+ * 규칙·처분 기준은 `docs/convention/composable-callback-defaults.md` 참고.
+ *
+ * ### 검사 대상
+ * app · feature 모듈 `src/main` 의
+ * 1. `@Composable` 함수 파라미터
+ * 2. 클래스 주 생성자 파라미터 — `ReceiverHomeActions` 처럼 콜백을 프로퍼티로 묶은
+ *    홀더 클래스도 같은 방식으로 미배선을 숨긴다.
+ *
+ * 이름이 `on`+대문자로 시작하고 기본값이 no-op 람다(`{}` · `{ }` · `{ _ -> }`)인 파라미터가
+ * 위반이다. "함수 타입인가" 는 따로 검사하지 않는다 — no-op 람다 기본값은 함수 타입에만
+ * 컴파일되므로 기본값 모양이 타입 검사를 대신하고, typealias 콜백까지 잡는다.
+ *
+ * ### 올바른 모델링
+ * - 실호출부가 전부 실값을 넘기면: 디폴트를 없앤다(required). 프리뷰·테스트는 `{}` 명시.
+ * - 상호작용이 진짜 선택적이면: nullable 핸들러(`onXxx: (() -> Unit)?`) + null 이면 UI 숨김,
+ *   또는 오버로드 분리. `= {}` 로 죽은 버튼을 그리지 않는다.
+ *
+ * ### [LEGACY_NO_OP_DEFAULT_FILES]
+ * 가드 도입 시점(#1388)에 남아 있던 잔여 파일. 모듈 담당별 후속 PR 이 청소하며 목록에서 뺀다.
+ * 목록에 있는 파일은 위반이 **있어도 없어도 통과**한다(관대 판정) — 파일을 청소하는 PR 과
+ * 목록을 갱신하는 PR 의 머지 순서가 develop 을 red 로 만들지 않게 하기 위해서다
+ * ([ResponseDtoContractKonsistTest] 의 #933 전례와 같은 구조). 이미 청소된 항목이 목록에
+ * 남아 있으면 아래 「해소된 항목은 경고로 알린다」 가 경고만 낸다.
+ */
+class NoOpCallbackDefaultKonsistTest {
+    @Test
+    fun `컴포저블 on 콜백 파라미터는 no-op 디폴트를 두지 않는다`() {
+        val violations = noOpCallbackDefaults().filterNot { it.isLegacyFile() }
+
+        check(violations.isEmpty()) {
+            buildString {
+                appendLine("on* 콜백 파라미터에 no-op 디폴트가 새로 추가됐다 (${violations.size}건).")
+                appendLine("배선을 빠뜨려도 컴파일이 통과해 조용히 no-op 이 된다 (#582 · #618 · #722 · #777 전례).")
+                appendLine()
+                violations.map(NoOpDefault::describe).sorted().forEach { appendLine("  $it") }
+                appendLine()
+                appendLine("실호출부가 전부 실값을 넘기면 디폴트를 없애고(프리뷰·테스트는 {} 명시),")
+                appendLine("진짜 선택적 상호작용이면 nullable 핸들러 + UI 숨김으로 모델링한다.")
+                appendLine("기준: docs/convention/composable-callback-defaults.md")
+            }
+        }
+    }
+
+    /**
+     * 해소된 항목이 목록에 남아 있으면 **경고만** 낸다.
+     *
+     * 실패시키면 「파일을 청소하는 PR」 과 「목록에서 빼는 PR」 이 서로를 깨뜨린다 —
+     * [ResponseDtoContractKonsistTest] 의 동명 테스트와 같은 이유다. 신규 유입 차단은
+     * 위 테스트가 담당하고, 이쪽은 목록 갱신 시점을 알리는 데 그친다.
+     */
+    @Test
+    fun `해소된 항목은 경고로 알린다`() {
+        val violatedPaths = noOpCallbackDefaults().map(NoOpDefault::path)
+        val stale =
+            LEGACY_NO_OP_DEFAULT_FILES.filter { suffix -> violatedPaths.none { it.endsWith(suffix) } }
+        if (stale.isEmpty()) return
+
+        println(
+            buildString {
+                appendLine("[경고] LEGACY_NO_OP_DEFAULT_FILES 에 이미 해소된 항목이 남아 있다 (${stale.size}건).")
+                appendLine("목록에서 지워야 다음 위반이 이 자리에 숨지 않는다.")
+                appendLine()
+                stale.sorted().forEach { appendLine("  $it") }
+            },
+        )
+    }
+
+    private fun noOpCallbackDefaults(): List<NoOpDefault> =
+        guardedFiles().flatMap { file ->
+            val composableFunctionParams =
+                file
+                    .functions()
+                    .filter { function -> function.annotations.any { it.name == COMPOSABLE } }
+                    .flatMap { function -> function.parameters.noOpCallbacks(file, function.name) }
+            val constructorParams =
+                file
+                    .classes()
+                    .flatMap { cls ->
+                        val parameters = cls.primaryConstructor?.parameters.orEmpty()
+                        parameters.noOpCallbacks(file, cls.name)
+                    }
+            composableFunctionParams + constructorParams
+        }
+
+    private fun List<KoParameterDeclaration>.noOpCallbacks(
+        file: KoFileDeclaration,
+        owner: String,
+    ): List<NoOpDefault> =
+        filter { parameter -> CALLBACK_NAME.containsMatchIn(parameter.name) && parameter.hasNoOpDefault() }
+            .map { parameter -> NoOpDefault(path = file.normalizedProjectPath(), owner = owner, parameter = parameter.name) }
+
+    private fun KoParameterDeclaration.hasNoOpDefault(): Boolean {
+        val normalized = defaultValue?.replace(WHITESPACE, "") ?: return false
+        return NO_OP_LAMBDA.matches(normalized)
+    }
+
+    private fun guardedFiles(): List<KoFileDeclaration> =
+        Konsist
+            .scopeFromProject()
+            .files
+            .filter { file ->
+                val path = file.normalizedProjectPath()
+                (path.startsWith("app/") || path.startsWith("feature/")) && "/src/main/" in path
+            }
+
+    private fun KoFileDeclaration.normalizedProjectPath(): String = projectPath.replace('\\', '/').trimStart('/')
+
+    private data class NoOpDefault(
+        val path: String,
+        val owner: String,
+        val parameter: String,
+    ) {
+        fun isLegacyFile(): Boolean = LEGACY_NO_OP_DEFAULT_FILES.any { path.endsWith(it) }
+
+        fun describe(): String = "$path — $owner($parameter)"
+    }
+
+    private companion object {
+        const val COMPOSABLE = "Composable"
+
+        /** `on` + 대문자로 시작하는 콜백 이름. */
+        val CALLBACK_NAME = Regex("""^on[A-Z]""")
+
+        /** 공백 제거 후 `{}` · `{->}` · `{_->}` · `{_,_->}` 꼴 — 아무것도 하지 않는 람다. */
+        val NO_OP_LAMBDA = Regex("""^\{(_(,_)*)?(->)?\}$""")
+
+        val WHITESPACE = Regex("""\s""")
+
+        /** afternote — PR #1336 이 같은 파일을 만지는 중이라 #1388 afternote 몫에서 제외한 1건. */
+        private val AFTERNOTE =
+            setOf(
+                "feature/afternote/presentation/author/detail/MemorialDetailScreen.kt",
+            )
+
+        /** home — #1388 모듈 몫 후속 PR 이 청소한다. */
+        private val HOME =
+            setOf(
+                "feature/home/presentation/WeeklySummaryGrid.kt",
+            )
+
+        /** mindrecord — #1388 모듈 몫 후속 PR 이 청소한다. */
+        private val MINDRECORD =
+            setOf(
+                "feature/mindrecord/presentation/component/DailyQuestionListCard.kt",
+                "feature/mindrecord/presentation/component/DiaryCard.kt",
+                "feature/mindrecord/presentation/component/DiaryComponent.kt",
+                "feature/mindrecord/presentation/component/KeyBoardToolBar.kt",
+                "feature/mindrecord/presentation/component/MemoriesCard.kt",
+                "feature/mindrecord/presentation/component/TodayQuestionCard.kt",
+                "feature/mindrecord/presentation/component/WeeklyReportReviewCard.kt",
+                "feature/mindrecord/presentation/component/WriteTextField.kt",
+                "feature/mindrecord/presentation/screen/receiver/ReceiverMindRecordScreen.kt",
+                "feature/mindrecord/presentation/screen/sender/DailyQuestionAnswerListScreen.kt",
+                "feature/mindrecord/presentation/screen/sender/DailyQuestionWriteScreen.kt",
+                "feature/mindrecord/presentation/screen/sender/DiaryScreen.kt",
+                "feature/mindrecord/presentation/screen/sender/DiaryWriteScreen.kt",
+                "feature/mindrecord/presentation/screen/sender/DraftListScreen.kt",
+                "feature/mindrecord/presentation/screen/sender/HomeScreen.kt",
+            )
+
+        /** receiver — #1388 모듈 몫 후속 PR 이 청소한다. */
+        private val RECEIVER =
+            setOf(
+                "feature/receiver/presentation/home/ReceiverHomeActions.kt",
+                "feature/receiver/presentation/summary/ContentSection.kt",
+                "feature/receiver/presentation/summary/ReceiverAfternoteScreen.kt",
+            )
+
+        /** timeletter — #1388 모듈 몫 후속 PR 이 청소한다 (TimeLetterWriteScreen 은 #778 과 조정). */
+        private val TIMELETTER =
+            setOf(
+                "feature/timeletter/presentation/component/DraftLetterItem.kt",
+                "feature/timeletter/presentation/component/TimeLetterBlockItem.kt",
+                "feature/timeletter/presentation/component/TimeLetterContent.kt",
+                "feature/timeletter/presentation/component/TimeletterListItem.kt",
+                "feature/timeletter/presentation/screen/recipient/RecipientTimeletterScreen.kt",
+                "feature/timeletter/presentation/screen/sender/TimeLetterWriteScreen.kt",
+                "feature/timeletter/presentation/screen/sender/TimeletterScreen.kt",
+            )
+
+        val LEGACY_NO_OP_DEFAULT_FILES = AFTERNOTE + HOME + MINDRECORD + RECEIVER + TIMELETTER
+    }
+}