diff --git a/Animal-Crossing-Wiki/Projects/App/Resources/en.lproj/Localizable.strings b/Animal-Crossing-Wiki/Projects/App/Resources/en.lproj/Localizable.strings
index 69538471..de6331dc 100644
--- a/Animal-Crossing-Wiki/Projects/App/Resources/en.lproj/Localizable.strings
+++ b/Animal-Crossing-Wiki/Projects/App/Resources/en.lproj/Localizable.strings
@@ -80,6 +80,7 @@ Find the villagers you have visited and tap the home icon on the villager's page
 "Restore complete" = "Restore complete";
 "Restored %d items" = "Restored %d items.";
 "Restore failed" = "Restore failed";
+"Unknown error" = "Unknown error";
 "No local backup found" = "No local backup found.";
 "Local backup info" = "Last local backup";
 "Local backup info format" = "%@ · %d items";
diff --git a/Animal-Crossing-Wiki/Projects/App/Resources/ko.lproj/Localizable.strings b/Animal-Crossing-Wiki/Projects/App/Resources/ko.lproj/Localizable.strings
index d46112fd..712534cf 100644
--- a/Animal-Crossing-Wiki/Projects/App/Resources/ko.lproj/Localizable.strings
+++ b/Animal-Crossing-Wiki/Projects/App/Resources/ko.lproj/Localizable.strings
@@ -82,6 +82,7 @@
 "Restore complete" = "복원 완료";
 "Restored %d items" = "%d개 항목을 복원했습니다.";
 "Restore failed" = "복원 실패";
+"Unknown error" = "알 수 없는 오류";
 "No local backup found" = "저장된 로컬 백업이 없습니다.";
 "Local backup info" = "마지막 로컬 백업";
 "Local backup info format" = "%@ · 항목 %d개";
diff --git a/Animal-Crossing-Wiki/Projects/App/Sources/AppCoordinator.swift b/Animal-Crossing-Wiki/Projects/App/Sources/AppCoordinator.swift
index 66e0668e..eb6b4d61 100644
--- a/Animal-Crossing-Wiki/Projects/App/Sources/AppCoordinator.swift
+++ b/Animal-Crossing-Wiki/Projects/App/Sources/AppCoordinator.swift
@@ -40,6 +40,7 @@ final class AppCoordinator: Coordinator {
 
         let animalsCoordinator = AnimalsCoordinator()
         animalsCoordinator.start()
+        animalsCoordinator.setUpParent(to: self)
         addViewController(animalsCoordinator.rootViewController, title: "animals".localized, icon: "icon-book-tabbar")
         childCoordinators.append(animalsCoordinator)
 
diff --git a/Animal-Crossing-Wiki/Projects/App/Sources/CoreDataStorage/DailyTaskStorage/CoreDataDailyTaskStorage.swift b/Animal-Crossing-Wiki/Projects/App/Sources/CoreDataStorage/DailyTaskStorage/CoreDataDailyTaskStorage.swift
index e970ee62..8b3d2cdd 100644
--- a/Animal-Crossing-Wiki/Projects/App/Sources/CoreDataStorage/DailyTaskStorage/CoreDataDailyTaskStorage.swift
+++ b/Animal-Crossing-Wiki/Projects/App/Sources/CoreDataStorage/DailyTaskStorage/CoreDataDailyTaskStorage.swift
@@ -90,6 +90,13 @@ final class CoreDataDailyTaskStorage: DailyTaskStorage {
                 let itemEntities = object.dailyTasks?.allObjects as? [DailyTaskEntity] ?? []
                 if let index = itemEntities.firstIndex(where: { $0.id == task.id }) {
                     var progressList = (itemEntities[index].progressList as? [Bool]) ?? []
+
+                    // CloudKit 부분 import 후 저장된 progressList가 짧을 수 있음 — 길이를 보정해
+                    // index out of range 크래시를 방지하고 손상된 데이터를 자가 치유한다.
+                    if progressList.count <= progressIndex {
+                        let padding = progressIndex + 1 - progressList.count
+                        progressList.append(contentsOf: Array(repeating: false, count: padding))
+                    }
                     progressList[progressIndex] = !progressList[progressIndex]
                     itemEntities[index].progressList = progressList as NSArray
                 }
diff --git a/Animal-Crossing-Wiki/Projects/App/Sources/CoreDataStorage/DailyTaskStorage/EntityMapping/DailyTaskEntity+Mapping.swift b/Animal-Crossing-Wiki/Projects/App/Sources/CoreDataStorage/DailyTaskStorage/EntityMapping/DailyTaskEntity+Mapping.swift
index 647a1519..2108f228 100644
--- a/Animal-Crossing-Wiki/Projects/App/Sources/CoreDataStorage/DailyTaskStorage/EntityMapping/DailyTaskEntity+Mapping.swift
+++ b/Animal-Crossing-Wiki/Projects/App/Sources/CoreDataStorage/DailyTaskStorage/EntityMapping/DailyTaskEntity+Mapping.swift
@@ -21,12 +21,22 @@ extension DailyTaskEntity {
     }
 
     func toDomain() -> DailyTask {
+        let amount = Int(self.amount)
+
+        // CloudKit 부분 import/sync reset 후 progressList가 nil이거나 amount보다 짧을 수 있음.
+        // UI는 amount 기준으로 체크박스를 만들기 때문에 길이를 amount에 맞춰 정규화해
+        // index out of range 크래시를 방지한다.
+        var progressList = (self.progressList as? [Bool]) ?? []
+        if progressList.count < amount {
+            progressList.append(contentsOf: Array(repeating: false, count: amount - progressList.count))
+        }
+
         return DailyTask(
             id: self.id ?? UUID(),
             name: self.name ?? "",
             icon: self.icon ?? "",
-            progressList: (self.progressList as? [Bool]) ?? [],
-            amount: Int(self.amount),
+            progressList: progressList,
+            amount: amount,
             createdDate: self.date ?? Date()
         )
     }
diff --git a/Animal-Crossing-Wiki/Projects/App/Sources/CoreDataStorage/SafetySnapshot/SafetySnapshotService.swift b/Animal-Crossing-Wiki/Projects/App/Sources/CoreDataStorage/SafetySnapshot/SafetySnapshotService.swift
index 582b9aba..0d7734a7 100644
--- a/Animal-Crossing-Wiki/Projects/App/Sources/CoreDataStorage/SafetySnapshot/SafetySnapshotService.swift
+++ b/Animal-Crossing-Wiki/Projects/App/Sources/CoreDataStorage/SafetySnapshot/SafetySnapshotService.swift
@@ -47,7 +47,9 @@ final class SafetySnapshotService {
     private static let debounceSeconds: TimeInterval = 30
 
     private let queue = DispatchQueue(label: "app.safety.snapshot", qos: .utility)
-    private var pendingWorkItem: DispatchWorkItem?
+
+    /// CoreData 저장 알림(임의 스레드)·main 스레드·sync-reset 알림이 동시에 접근하므로 lock으로 보호
+    private let _pendingWorkItem = OSAllocatedUnfairLock<DispatchWorkItem?>(initialState: nil)
     private var observers: [NSObjectProtocol] = []
     private let containerProvider: () -> NSPersistentContainer
     private let snapshotDirectoryProvider: () -> URL?
@@ -131,24 +133,33 @@ final class SafetySnapshotService {
             NotificationCenter.default.removeObserver(observer)
         }
         observers.removeAll()
-        pendingWorkItem?.cancel()
-        pendingWorkItem = nil
+        _pendingWorkItem.withLock { item in
+            item?.cancel()
+            item = nil
+        }
     }
 
     private func scheduleSnapshot() {
-        pendingWorkItem?.cancel()
         let workItem = DispatchWorkItem { [weak self] in
             self?.writeSnapshotNow()
         }
-        pendingWorkItem = workItem
+        _pendingWorkItem.withLock { item in
+            item?.cancel()
+            item = workItem
+        }
         queue.asyncAfter(deadline: .now() + Self.debounceSeconds, execute: workItem)
     }
 
     /// 강제 저장 — 앱 종료 직전/sync-reset 직전 등에서 flushing 용도.
+    /// debounce 중인 쓰기와 파일 I/O가 겹치지 않도록 queue에서 동기 실행한다.
     func flushNow() {
-        pendingWorkItem?.cancel()
-        pendingWorkItem = nil
-        writeSnapshotNow()
+        _pendingWorkItem.withLock { item in
+            item?.cancel()
+            item = nil
+        }
+        queue.sync { [weak self] in
+            self?.writeSnapshotNow()
+        }
     }
 
     private func writeSnapshotNow() {
diff --git a/Animal-Crossing-Wiki/Projects/App/Sources/CoreDataStorage/VillagersLikeStorage/EntityMapping/NPCLikeEntity+Mapping.swift b/Animal-Crossing-Wiki/Projects/App/Sources/CoreDataStorage/VillagersLikeStorage/EntityMapping/NPCLikeEntity+Mapping.swift
index f4a40e11..81d92b9d 100644
--- a/Animal-Crossing-Wiki/Projects/App/Sources/CoreDataStorage/VillagersLikeStorage/EntityMapping/NPCLikeEntity+Mapping.swift
+++ b/Animal-Crossing-Wiki/Projects/App/Sources/CoreDataStorage/VillagersLikeStorage/EntityMapping/NPCLikeEntity+Mapping.swift
@@ -31,7 +31,7 @@ extension NPCLikeEntity {
             iconImage: self.iconImage ?? "",
             photoImage: self.photoImage ?? "",
             gender: Gender(rawValue: self.gender ?? "") ?? .male,
-            genderAsia: Gender(rawValue: self.gender ?? "") ?? .male,
+            genderAsia: Gender(rawValue: self.genderAsia ?? "") ?? .male,
             species: self.species ?? "",
             birthday: self.birthday ?? "",
             appearanceLocation: appearanceLocation ?? [],
diff --git a/Animal-Crossing-Wiki/Projects/App/Sources/Models/DailyTask.swift b/Animal-Crossing-Wiki/Projects/App/Sources/Models/DailyTask.swift
index 7d5ec9fe..fe6d9458 100644
--- a/Animal-Crossing-Wiki/Projects/App/Sources/Models/DailyTask.swift
+++ b/Animal-Crossing-Wiki/Projects/App/Sources/Models/DailyTask.swift
@@ -16,6 +16,10 @@ struct DailyTask {
     let createdDate: Date
 
     mutating func toggleCompleted(_ index: Int) {
+        // 동기화로 progressList가 amount보다 짧아질 수 있음 — 길이를 보정해 크래시 방지
+        if progressList.count <= index {
+            progressList.append(contentsOf: Array(repeating: false, count: index + 1 - progressList.count))
+        }
         self.progressList[index].toggle()
     }
 
diff --git a/Animal-Crossing-Wiki/Projects/App/Sources/Presentation/Animals/ViewModels/NPCCellReactor.swift b/Animal-Crossing-Wiki/Projects/App/Sources/Presentation/Animals/ViewModels/NPCCellReactor.swift
index 13b4e559..44aa7f22 100644
--- a/Animal-Crossing-Wiki/Projects/App/Sources/Presentation/Animals/ViewModels/NPCCellReactor.swift
+++ b/Animal-Crossing-Wiki/Projects/App/Sources/Presentation/Animals/ViewModels/NPCCellReactor.swift
@@ -63,6 +63,7 @@ final class NPCCellReactor: Reactor {
             HapticManager.shared.impact(style: .medium)
             Items.shared.updateNPCLike(npc)
             likeStorage.update(npc)
+            newState.isLiked = !(newState.isLiked ?? false)
         }
         return newState
     }
diff --git a/Animal-Crossing-Wiki/Projects/App/Sources/Presentation/Animals/ViewModels/VillagersCellReactor.swift b/Animal-Crossing-Wiki/Projects/App/Sources/Presentation/Animals/ViewModels/VillagersCellReactor.swift
index 4d0b2707..dcf2fcb8 100644
--- a/Animal-Crossing-Wiki/Projects/App/Sources/Presentation/Animals/ViewModels/VillagersCellReactor.swift
+++ b/Animal-Crossing-Wiki/Projects/App/Sources/Presentation/Animals/ViewModels/VillagersCellReactor.swift
@@ -84,11 +84,13 @@ final class VillagersCellReactor: Reactor {
             HapticManager.shared.impact(style: .medium)
             Items.shared.updateVillagerHouse(villager)
             houseStorage.update(villager)
+            newState.isResident = !(newState.isResident ?? false)
 
         case .updateLike:
             HapticManager.shared.impact(style: .medium)
             Items.shared.updateVillagerLike(villager)
             likeStorage.update(villager)
+            newState.isLiked = !(newState.isLiked ?? false)
         }
         return newState
     }
diff --git a/Animal-Crossing-Wiki/Projects/App/Sources/Utility/Items.swift b/Animal-Crossing-Wiki/Projects/App/Sources/Utility/Items.swift
index 4c7c5ff0..0ea8cd5e 100644
--- a/Animal-Crossing-Wiki/Projects/App/Sources/Utility/Items.swift
+++ b/Animal-Crossing-Wiki/Projects/App/Sources/Utility/Items.swift
@@ -499,6 +499,7 @@ extension Items {
     func reset() {
         villagersLike.accept([])
         villagersHouse.accept([])
+        npcLike.accept([])
         let currentItems = userItems.value.map { $0.key }
         var resetItem = userItems.value
         currentItems.forEach { category in
diff --git a/Animal-Crossing-Wiki/Projects/App/Sources/Utility/MusicPlayerManager.swift b/Animal-Crossing-Wiki/Projects/App/Sources/Utility/MusicPlayerManager.swift
index b8b0ca06..0eef20df 100644
--- a/Animal-Crossing-Wiki/Projects/App/Sources/Utility/MusicPlayerManager.swift
+++ b/Animal-Crossing-Wiki/Projects/App/Sources/Utility/MusicPlayerManager.swift
@@ -23,8 +23,10 @@ final class MusicPlayerManager {
     static let shared = MusicPlayerManager()
 
     private let disposeBag = DisposeBag()
+    private var backgroundDisposeBag = DisposeBag()
     private var player: AVPlayer?
     private var timer: Timer?
+    private var endPlaybackObserver: NSObjectProtocol?
 
     private let isPlaying = BehaviorRelay<Bool?>(value: nil)
     private let currentSong = BehaviorRelay<Item?>(value: nil)
@@ -54,6 +56,9 @@ final class MusicPlayerManager {
             .compactMap { URL(string: $0) }
             .subscribe(with: self, onNext: { owner, musicURL in
                 owner.player = AVPlayer(url: musicURL)
+                // 곡이 바뀔 때마다(player 재생성) 종료 알림 옵저버를 재등록해
+                // 자동 다음 곡/반복 재생이 끊기지 않도록 보장한다.
+                owner.setUpNotification()
             }).disposed(by: disposeBag)
 
         currentSong
@@ -144,16 +149,25 @@ final class MusicPlayerManager {
     }
 
     private func setUpNotification() {
-        NotificationCenter.default.removeObserver(self, name: .AVPlayerItemDidPlayToEndTime, object: nil)
-        
-        NotificationCenter.default.addObserver(
+        // block 기반 옵저버는 removeObserver(self,...)로 제거되지 않으므로 토큰을 보관해 제거한다.
+        // object를 특정 AVPlayerItem에 바인딩하면 곡 전환(changeSong) 후 알림을 못 받으므로
+        // object: nil로 등록하고 핸들러에서 현재 재생 item인지 확인한다.
+        if let endPlaybackObserver {
+            NotificationCenter.default.removeObserver(endPlaybackObserver)
+        }
+
+        endPlaybackObserver = NotificationCenter.default.addObserver(
             forName: .AVPlayerItemDidPlayToEndTime,
-            object: player?.currentItem,
+            object: nil,
             queue: .main
-        ) { [weak self] _ in
+        ) { [weak self] notification in
             guard let owner = self else {
                 return
             }
+            guard let endedItem = notification.object as? AVPlayerItem,
+                  endedItem === owner.player?.currentItem else {
+                return
+            }
             owner.playerProgress.accept(0)
             owner.elapsedTime.accept("0:00")
             owner.isPlaying.accept(false)
@@ -180,6 +194,9 @@ final class MusicPlayerManager {
             playingInfo[MPMediaItemPropertyAlbumTitle] = "K.K. Slider"
             playingInfo[MPMediaItemPropertyTitle] = currentSong.translations.localizedName()
 
+            // 곡 전환 시 이전 곡의 아트워크 다운로드를 취소해, 늦게 도착한 이미지가
+            // 잠금화면 now playing 정보를 덮어쓰는 것을 방지한다.
+            backgroundDisposeBag = DisposeBag()
             UIImage.downloadImage(urlString: currentSong.image ?? "")
                 .compactMap { $0 }
                 .subscribe(onNext: { image in
@@ -189,7 +206,7 @@ final class MusicPlayerManager {
                         }
                     )
                     MPNowPlayingInfoCenter.default().nowPlayingInfo = playingInfo
-                }).disposed(by: disposeBag)
+                }).disposed(by: backgroundDisposeBag)
         }
     }
 
@@ -295,7 +312,6 @@ extension MusicPlayerManager {
         close()
         currentSong.accept(item)
         isPlaying.accept(true)
-        setUpNotification()
     }
 
     func close() {
@@ -309,9 +325,12 @@ extension MusicPlayerManager {
         elapsedTime.accept("0:00")
         durationTime.accept("0:00")
         playerProgress.accept(0)
-        
-        NotificationCenter.default.removeObserver(self, name: .AVPlayerItemDidPlayToEndTime, object: nil)
-        
+
+        if let endPlaybackObserver {
+            NotificationCenter.default.removeObserver(endPlaybackObserver)
+            self.endPlaybackObserver = nil
+        }
+
         try? AVAudioSession.sharedInstance().setActive(false, options: [])
     }
 }
diff --git a/Animal-Crossing-Wiki/Projects/App/Tests/CoreDataStorage/CoreDataStorageICloudResetTests.swift b/Animal-Crossing-Wiki/Projects/App/Tests/CoreDataStorage/CoreDataStorageICloudResetTests.swift
index fbdf71d3..b7882932 100644
--- a/Animal-Crossing-Wiki/Projects/App/Tests/CoreDataStorage/CoreDataStorageICloudResetTests.swift
+++ b/Animal-Crossing-Wiki/Projects/App/Tests/CoreDataStorage/CoreDataStorageICloudResetTests.swift
@@ -324,6 +324,56 @@ final class CoreDataStorageICloudResetTests: XCTestCase {
         XCTAssertTrue(storage.isWithinRecoveryGracePeriod)
     }
 
+    func testCorruptedProgressListNormalizedOnToDomain() throws {
+        let storage = try makeStorage()
+        let context = storage.persistentContainer.viewContext
+
+        let userCollection = try insertUserCollection(in: context)
+        let taskEntity = try insertDailyTask(in: context, linkedTo: userCollection)
+        taskEntity.amount = 6
+        taskEntity.progressList = [] as NSArray // CloudKit 부분 import로 손상된 상태
+        try context.save()
+
+        let domain = taskEntity.toDomain()
+
+        XCTAssertEqual(domain.progressList.count, 6)
+        XCTAssertEqual(domain.progressList, Array(repeating: false, count: 6))
+    }
+
+    func testToggleCompletedOnCorruptedProgressListDoesNotCrashAndHeals() throws {
+        let storage = try makeStorage()
+        let context = storage.persistentContainer.viewContext
+
+        let userCollection = try insertUserCollection(in: context)
+        let taskEntity = try insertDailyTask(in: context, linkedTo: userCollection)
+        taskEntity.amount = 6
+        taskEntity.progressList = [] as NSArray
+        try context.save()
+
+        var domainTask = taskEntity.toDomain()
+
+        // 모델 toggle — 손상 길이에서도 크래시 없이 보정 후 토글
+        domainTask.toggleCompleted(5)
+        XCTAssertEqual(domainTask.progressList.count, 6)
+        XCTAssertTrue(domainTask.progressList[5])
+
+        // 저장소 toggle — background context에서 보정 후 저장되는지 폴링으로 확인
+        let taskStorage = CoreDataDailyTaskStorage(coreDataStorage: storage)
+        taskStorage.toggleCompleted(domainTask, progressIndex: 5)
+
+        let deadline = Date().addingTimeInterval(5)
+        var healed = false
+        while !healed && Date() < deadline {
+            context.refreshAllObjects()
+            if let stored = taskEntity.progressList as? [Bool], stored.count == 6, stored[5] {
+                healed = true
+            } else {
+                RunLoop.current.run(until: Date().addingTimeInterval(0.05))
+            }
+        }
+        XCTAssertTrue(healed, "storage toggleCompleted should heal corrupted progressList without crashing")
+    }
+
     func testSyncProtectionStateDetectsSuppressedEmptyCollection() throws {
         let storage = try makeStorage()
         let context = storage.persistentContainer.viewContext
diff --git a/docs/features/dashboard.md b/docs/features/dashboard.md
index 10051c5d..9ad478fd 100644
--- a/docs/features/dashboard.md
+++ b/docs/features/dashboard.md
@@ -84,6 +84,10 @@ viewController.setUpViewModels(
 
 ## Special Patterns
 
+- **DailyTask progressList 정규화**: CloudKit 부분 import/sync reset 후 `DailyTaskEntity.progressList`가
+  nil이거나 `amount`보다 짧을 수 있다. UI는 `amount` 기준으로 체크박스를 만들기 때문에
+  `toDomain()`에서 길이를 `amount`로 보정하고, `toggleCompleted`(모델·storage 양쪽)도
+  보정 후 토글한다 — index out of range 크래시 방지 + 손상 데이터 자가 치유
 - **CustomTaskViewControllerDelegate**: DashboardCoordinator가 IconChooser → CustomTaskVC 간 아이콘 선택 결과를 전달하는 delegate
 - **showAlert()**: DashboardCoordinator의 `showAlert(title:message:) -> Observable<Bool>` 메서드로 확인 다이얼로그 표시
 - **showRecoveryResultAlert()**: (TEMPORARY) iCloud 데이터 복구 결과 알림. 성공 시 앱 종료 유도
diff --git a/docs/features/icloud-sync.md b/docs/features/icloud-sync.md
index bed52d6e..ff1a0e98 100644
--- a/docs/features/icloud-sync.md
+++ b/docs/features/icloud-sync.md
@@ -273,6 +273,9 @@ CloudKit import, remote change, sync reset 직전에는 최신 로컬 상태를
 - 스냅샷 파일은 첫 잠금 해제 후 백그라운드 CloudKit flush에서도 갱신될 수 있도록 `completeUntilFirstUserAuthentication` 보호 등급으로 저장한다.
 - 파일은 기기/iCloud 백업에서 제외하여 Core Data 원본과 별도로 장기 보관되지 않게 한다.
 - 복원은 `wipeExistingCollection → snapshot.apply → context.save()`를 단일 context rollback 경계에 묶는다. 중간 실패 시 기존 로컬 컬렉션 삭제가 저장되지 않는다.
+- debounce용 `pendingWorkItem`은 CoreData 저장 알림(임의 스레드)·main 스레드·sync-reset 알림이
+  동시에 접근하므로 `OSAllocatedUnfairLock`으로 보호하고, `flushNow()`는 debounce 쓰기와
+  파일 I/O가 겹치지 않도록 전용 queue에서 동기 실행한다.
 
 ## Manual Consolidation (중복/고아 데이터 정리)
 
diff --git a/docs/features/music-player.md b/docs/features/music-player.md
index dbd49bde..bd7a20d9 100644
--- a/docs/features/music-player.md
+++ b/docs/features/music-player.md
@@ -49,6 +49,12 @@ topAnchor constraint 조절 + spring animation으로 minimize/maximize 전환.
 - `MPRemoteCommandCenter` 연동 (잠금화면 컨트롤)
 - 재생 모드: shuffle, fullRepeat, oneSongRepeat
 
+**곡 종료 알림 (`AVPlayerItemDidPlayToEndTime`) 처리 규칙**:
+- block 기반 옵저버는 `removeObserver(self,...)`로 제거되지 않으므로 **토큰**(`endPlaybackObserver`)을 보관해 제거한다 (누적 등록 시 자동 다음 곡이 여러 번 실행되는 버그 방지)
+- `object: nil`로 등록하고 핸들러에서 `notification.object === player?.currentItem`을 확인한다 — 특정 `AVPlayerItem`에 바인딩하면 곡 전환 후 알림을 받지 못함
+- 등록 지점은 한 곳: `currentSong` 구독에서 `AVPlayer` 재생성 직후 `setUpNotification()` 호출
+- 잠금화면 아트워크 다운로드는 `backgroundDisposeBag`(곡마다 재생성)에 담아, 이전 곡 이미지가 늦게 도착해 now playing 정보를 덮어쓰는 것을 방지
+
 ## 데이터 흐름
 
 ```