Add persistent local music catalog

.gitignore

@@ -118,3 +118,7 @@ playground.xcworkspace
 # Package.resolved
 packages/apple/**/.build/
 **/.build/
+
+# Xcode local build artifacts
+.derivedData/
+DerivedData/

apps/apple/VelodyMac/Sources/LocalMusicScanner.swift

@@ -1,6 +1,6 @@
 import AVFoundation
+import CryptoKit
 import Foundation
-import VelodyDomain
 import VelodyPersistence
 
 final class AVFoundationMetadataReader: MetadataReader {
@@ -20,17 +20,20 @@ final class AVFoundationMetadataReader: MetadataReader {
 
 final class FileSystemLocalMusicScanner: LocalMusicScanner {
     private let metadataReader: any MetadataReader
+    private let fileHasher: SHA256FileHasher
     private let fileManager: FileManager
 
     init(
         metadataReader: any MetadataReader,
+        fileHasher: SHA256FileHasher = SHA256FileHasher(),
         fileManager: FileManager = .default
     ) {
         self.metadataReader = metadataReader
+        self.fileHasher = fileHasher
         self.fileManager = fileManager
     }
 
-    func scanFolder(at folderURL: URL) async throws -> [LibraryTrack] {
+    func scanFolder(at folderURL: URL) async throws -> [ScannedLocalTrack] {
         let hasScopedAccess = folderURL.startAccessingSecurityScopedResource()
         defer {
             if hasScopedAccess {
@@ -40,13 +43,16 @@ final class FileSystemLocalMusicScanner: LocalMusicScanner {
 
         guard let enumerator = fileManager.enumerator(
             at: folderURL,
-            includingPropertiesForKeys: [.isRegularFileKey],
+            includingPropertiesForKeys: [
+                .isRegularFileKey,
+                .contentModificationDateKey,
+            ],
             options: [.skipsHiddenFiles, .skipsPackageDescendants]
         ) else {
             throw CocoaError(.fileReadUnknown)
         }
 
-        var discoveredTracks: [LibraryTrack] = []
+        var discoveredTracks: [ScannedLocalTrack] = []
 
         for case let fileURL as URL in enumerator {
             guard shouldScan(fileURL) else {
@@ -54,30 +60,32 @@ final class FileSystemLocalMusicScanner: LocalMusicScanner {
             }
 
             let fallbackTitle = fileURL.deletingPathExtension().lastPathComponent
+            let sha256 = try fileHasher.hashFile(at: fileURL)
+            let fileModifiedAt = modificationDate(for: fileURL)
 
             do {
                 let metadata = try await metadataReader.readMetadata(for: fileURL)
                 discoveredTracks.append(
-                    LibraryTrack(
-                        id: fileURL.path,
+                    ScannedLocalTrack(
                         title: metadata.title?.trimmedNonEmpty ?? fallbackTitle,
                         artist: metadata.artist?.trimmedNonEmpty ?? "Unknown Artist",
                         album: metadata.album?.trimmedNonEmpty,
                         durationSeconds: metadata.durationSeconds,
                         localFilePath: fileURL.path,
-                        sha256: nil
+                        sha256: sha256,
+                        fileModifiedAt: fileModifiedAt
                     )
                 )
             } catch {
                 discoveredTracks.append(
-                    LibraryTrack(
-                        id: fileURL.path,
+                    ScannedLocalTrack(
                         title: fallbackTitle,
                         artist: "Unknown Artist",
                         album: nil,
                         durationSeconds: nil,
                         localFilePath: fileURL.path,
-                        sha256: nil
+                        sha256: sha256,
+                        fileModifiedAt: fileModifiedAt
                     )
                 )
             }
@@ -101,6 +109,46 @@ final class FileSystemLocalMusicScanner: LocalMusicScanner {
         let resourceValues = try? fileURL.resourceValues(forKeys: [.isRegularFileKey])
         return resourceValues?.isRegularFile == true
     }
+
+    private func modificationDate(for fileURL: URL) -> Date {
+        if let resourceValues = try? fileURL.resourceValues(forKeys: [.contentModificationDateKey]),
+           let contentModificationDate = resourceValues.contentModificationDate
+        {
+            return contentModificationDate
+        }
+
+        if let attributes = try? fileManager.attributesOfItem(atPath: fileURL.path),
+           let modificationDate = attributes[.modificationDate] as? Date
+        {
+            return modificationDate
+        }
+
+        return .distantPast
+    }
+}
+
+final class SHA256FileHasher {
+    private let bufferSize = 1_048_576
+
+    func hashFile(at fileURL: URL) throws -> String {
+        let fileHandle = try FileHandle(forReadingFrom: fileURL)
+        defer {
+            try? fileHandle.close()
+        }
+
+        var hasher = SHA256()
+
+        while true {
+            let data = try fileHandle.read(upToCount: bufferSize) ?? Data()
+            if data.isEmpty {
+                break
+            }
+
+            hasher.update(data: data)
+        }
+
+        return hasher.finalize().map { String(format: "%02x", $0) }.joined()
+    }
 }
 
 private extension Array where Element == AVMetadataItem {

apps/apple/VelodyMac/Sources/MacLibraryViewModel.swift

@@ -26,10 +26,10 @@ final class MacLibraryViewModel {
     var isRunningSyncBootstrap = false
 
     private let folderAccessService: any VelodyPersistence.FolderAccessService
+    private let catalogService: any LocalCatalogService
     private let localMusicScanner: any LocalMusicScanner
     private let keychainService: any KeychainService
     private let userDefaults: UserDefaults
-    private let store = InMemoryLocalLibraryStore()
     private var hasLoaded = false
 
     init(
@@ -40,8 +40,10 @@ final class MacLibraryViewModel {
         let localMusicScanner = FileSystemLocalMusicScanner(
             metadataReader: AVFoundationMetadataReader()
         )
+        let repository = Self.makeTrackRepository()
 
         self.folderAccessService = folderAccessService
+        self.catalogService = DefaultLocalCatalogService(repository: repository)
         self.localMusicScanner = localMusicScanner
         self.keychainService = keychainService
         self.userDefaults = userDefaults
@@ -57,8 +59,13 @@ final class MacLibraryViewModel {
     func loadIfNeeded() async {
         guard !hasLoaded else { return }
         hasLoaded = true
-        tracks = await store.loadTracks()
+        do {
+            tracks = try await catalogService.loadActiveLocalTracks()
             discoveredTrackCount = tracks.count
+        } catch {
+            scanStatus = "Failed to load saved catalog: \(error.localizedDescription)"
+        }
+
         await restoreDeviceIdentity()
     }
 
@@ -69,7 +76,11 @@ final class MacLibraryViewModel {
             tracks = []
             discoveredTrackCount = 0
             Task {
-                await store.replaceTracks([])
+                do {
+                    try await catalogService.resetLocalCatalog()
+                } catch {
+                    scanStatus = "Failed to reset saved catalog: \(error.localizedDescription)"
+                }
             }
         }
     }
@@ -88,10 +99,17 @@ final class MacLibraryViewModel {
 
         do {
             let discoveredTracks = try await localMusicScanner.scanFolder(at: folderURL)
-            await store.replaceTracks(discoveredTracks)
-            tracks = await store.loadTracks()
+            let scanResult = try await catalogService.reconcileScanResults(
+                discoveredTracks,
+                in: folderURL,
+                scannedAt: Date()
+            )
+            tracks = scanResult.tracks
             discoveredTrackCount = tracks.count
-            scanStatus = "Scan finished. Found \(discoveredTrackCount) MP3 file(s)."
+            scanStatus = Self.scanStatus(
+                for: scanResult,
+                activeTrackCount: discoveredTrackCount
+            )
         } catch {
             scanStatus = "Scan failed: \(error.localizedDescription)"
         }
@@ -231,6 +249,21 @@ final class MacLibraryViewModel {
         URLSessionVelodyAPIClient(environment: environment)
     }
 
+    private static func makeTrackRepository() -> any TrackRepository {
+        if let repository = try? SwiftDataTrackRepository() {
+            return repository
+        }
+
+        return InMemoryTrackRepository()
+    }
+
+    private static func scanStatus(
+        for result: LocalCatalogScanResult,
+        activeTrackCount: Int
+    ) -> String {
+        "Scan finished. Active: \(activeTrackCount). Added: \(result.insertedTrackCount). Updated: \(result.updatedTrackCount). Reactivated: \(result.reactivatedTrackCount). Deleted: \(result.deletedTrackCount). Duplicates skipped: \(result.skippedDuplicateTrackCount)."
+    }
+
     private static var currentAppVersion: String {
         if let shortVersion = Bundle.main.object(forInfoDictionaryKey: "CFBundleShortVersionString") as? String,
            !shortVersion.isEmpty

apps/apple/VelodyiPhone/Sources/iPhoneLibraryViewModel.swift

@@ -11,25 +11,38 @@ final class iPhoneLibraryViewModel {
     var tracks: [LibraryTrack] = []
     var syncStatus = "Offline library not synced yet"
 
-    private let store = InMemoryLocalLibraryStore()
+    private let store: any LocalLibraryStore
     private let syncCoordinator: PlaceholderSyncCoordinator
     private var hasLoaded = false
 
     init() {
+        let repository = Self.makeTrackRepository()
         let environment = ServerEnvironment(
             baseURL: ServerEnvironment.defaultLocalBaseURL,
             appVersion: "0.1.0"
         )
         let apiClient = StubVelodyAPIClient(environment: environment)
+        self.store = repository
         self.syncCoordinator = PlaceholderSyncCoordinator(
             apiClient: apiClient,
-            store: store
+            store: repository
         )
     }
 
     func loadIfNeeded() async {
         guard !hasLoaded else { return }
         hasLoaded = true
+
+        do {
+            let persistedTracks = try await store.loadTracks()
+            if !persistedTracks.isEmpty {
+                tracks = persistedTracks
+                syncStatus = "Loaded \(persistedTracks.count) cached track(s) from local storage."
+            }
+        } catch {
+            syncStatus = "Failed to load cached catalog: \(error.localizedDescription)"
+        }
+
         await refreshSync()
     }
 
@@ -42,4 +55,12 @@ final class iPhoneLibraryViewModel {
             syncStatus = "Sync placeholder failed: \(error.localizedDescription)"
         }
     }
+
+    private static func makeTrackRepository() -> any TrackRepository {
+        if let repository = try? SwiftDataTrackRepository() {
+            return repository
+        }
+
+        return InMemoryTrackRepository()
+    }
 }

backend/prisma/migrations/20260528090629_add_user_ownership_and_local_catalog/migration.sql

@@ -0,0 +1,26 @@
+-- AlterTable
+ALTER TABLE "artwork_assets" ALTER COLUMN "id" DROP DEFAULT;
+
+-- AlterTable
+ALTER TABLE "audio_assets" ALTER COLUMN "id" DROP DEFAULT;
+
+-- AlterTable
+ALTER TABLE "device_sync_cursors" ALTER COLUMN "updated_at" DROP DEFAULT;
+
+-- AlterTable
+ALTER TABLE "devices" ALTER COLUMN "id" DROP DEFAULT,
+ALTER COLUMN "updated_at" DROP DEFAULT;
+
+-- AlterTable
+ALTER TABLE "tracks" ALTER COLUMN "id" DROP DEFAULT,
+ALTER COLUMN "updated_at" DROP DEFAULT;
+
+-- AlterTable
+ALTER TABLE "upload_sessions" ALTER COLUMN "id" DROP DEFAULT,
+ALTER COLUMN "updated_at" DROP DEFAULT;
+
+-- RenameIndex
+ALTER INDEX "artwork_assets_storage_key" RENAME TO "artwork_assets_storage_key_key";
+
+-- RenameIndex
+ALTER INDEX "audio_assets_storage_key" RENAME TO "audio_assets_storage_key_key";

backend/prisma/migrations/migration_lock.toml

@@ -1,2 +1,3 @@
 # Please do not edit this file manually
+# It should be added in your version-control system (e.g., Git)
 provider = "postgresql"

packages/apple/VelodyPersistence/Package.swift

@@ -21,5 +21,12 @@ let package = Package(
             name: "VelodyPersistence",
             dependencies: ["VelodyDomain"]
         ),
+        .testTarget(
+            name: "VelodyPersistenceTests",
+            dependencies: [
+                "VelodyDomain",
+                "VelodyPersistence",
+            ]
+        ),
     ]
 )

packages/apple/VelodyPersistence/Sources/VelodyPersistence/LocalCatalogService.swift

@@ -0,0 +1,231 @@
+import Foundation
+import VelodyDomain
+
+public protocol LocalCatalogService: Sendable {
+    func loadActiveLocalTracks() async throws -> [LibraryTrack]
+    func reconcileScanResults(
+        _ scannedTracks: [ScannedLocalTrack],
+        in folderURL: URL,
+        scannedAt: Date
+    ) async throws -> LocalCatalogScanResult
+    func resetLocalCatalog() async throws
+}
+
+public actor DefaultLocalCatalogService: LocalCatalogService {
+    private let repository: any TrackRepository
+
+    public init(repository: any TrackRepository) {
+        self.repository = repository
+    }
+
+    public func loadActiveLocalTracks() async throws -> [LibraryTrack] {
+        try await repository.loadLocalTracks(
+            origin: .localScan,
+            includeDeleted: false
+        ).map(\.libraryTrack)
+    }
+
+    public func reconcileScanResults(
+        _ scannedTracks: [ScannedLocalTrack],
+        in folderURL: URL,
+        scannedAt: Date = Date()
+    ) async throws -> LocalCatalogScanResult {
+        let groupedTracks = Dictionary(grouping: scannedTracks, by: \.deduplicationKey)
+        let presentFilePaths = Set(scannedTracks.map(\.localFilePath))
+
+        var insertedTrackCount = 0
+        var updatedTrackCount = 0
+        var reactivatedTrackCount = 0
+        var deletedTrackCount = 0
+        var unchangedTrackCount = 0
+
+        for deduplicationKey in groupedTracks.keys.sorted() {
+            guard let groupedDuplicates = groupedTracks[deduplicationKey] else {
+                continue
+            }
+
+            let existingTrack = try await repository.findTrack(
+                deduplicationKey: deduplicationKey
+            )
+            let chosenTrack = preferredTrack(
+                from: groupedDuplicates,
+                preferredPath: existingTrack?.localFilePath
+            )
+
+            let existingTrackByPath = try await repository.findTrack(
+                localFilePath: chosenTrack.localFilePath,
+                origin: .localScan
+            )
+
+            let resolution = try await persistChosenTrack(
+                chosenTrack,
+                existingTrackBySHA: existingTrack,
+                existingTrackByPath: existingTrackByPath,
+                scannedAt: scannedAt
+            )
+
+            switch resolution {
+            case .inserted:
+                insertedTrackCount += 1
+            case .updated:
+                updatedTrackCount += 1
+            case .reactivated:
+                reactivatedTrackCount += 1
+            case .unchanged:
+                unchangedTrackCount += 1
+            case .merged(let additionalDeletedTrackCount):
+                updatedTrackCount += 1
+                deletedTrackCount += additionalDeletedTrackCount
+            case .mergedReactivated(let additionalDeletedTrackCount):
+                reactivatedTrackCount += 1
+                deletedTrackCount += additionalDeletedTrackCount
+            }
+        }
+
+        deletedTrackCount += try await repository.markDeletedLocalTracks(
+            missingFrom: presentFilePaths,
+            under: folderURL.path,
+            scannedAt: scannedAt
+        )
+
+        let activeTracks = try await loadActiveLocalTracks()
+
+        return LocalCatalogScanResult(
+            tracks: activeTracks,
+            insertedTrackCount: insertedTrackCount,
+            updatedTrackCount: updatedTrackCount,
+            reactivatedTrackCount: reactivatedTrackCount,
+            deletedTrackCount: deletedTrackCount,
+            skippedDuplicateTrackCount: scannedTracks.count - groupedTracks.count,
+            unchangedTrackCount: unchangedTrackCount
+        )
+    }
+
+    public func resetLocalCatalog() async throws {
+        try await repository.removeTracks(origin: .localScan)
+    }
+
+    private func persistChosenTrack(
+        _ scannedTrack: ScannedLocalTrack,
+        existingTrackBySHA: LocalTrack?,
+        existingTrackByPath: LocalTrack?,
+        scannedAt: Date
+    ) async throws -> TrackResolution {
+        if let existingTrackBySHA,
+           let existingTrackByPath,
+           existingTrackBySHA.id != existingTrackByPath.id
+        {
+            let canonicalTrack = mergedTrack(
+                existingTrackBySHA,
+                with: scannedTrack,
+                scannedAt: scannedAt
+            )
+
+            try await repository.saveLocalTrack(canonicalTrack.track)
+
+            if !existingTrackByPath.isDeleted {
+                var supersededTrack = existingTrackByPath
+                supersededTrack.isDeleted = true
+                supersededTrack.deletedAt = scannedAt
+                supersededTrack.lastScannedAt = scannedAt
+                supersededTrack.updatedAt = scannedAt
+                try await repository.saveLocalTrack(supersededTrack)
+            }
+
+            return canonicalTrack.wasDeleted
+                ? .mergedReactivated(additionalDeletedTrackCount: existingTrackByPath.isDeleted ? 0 : 1)
+                : .merged(additionalDeletedTrackCount: existingTrackByPath.isDeleted ? 0 : 1)
+        }
+
+        if let existingTrack = existingTrackBySHA ?? existingTrackByPath {
+            let merged = mergedTrack(existingTrack, with: scannedTrack, scannedAt: scannedAt)
+            try await repository.saveLocalTrack(merged.track)
+
+            if merged.wasDeleted {
+                return .reactivated
+            }
+
+            return merged.didChange ? .updated : .unchanged
+        }
+
+        try await repository.saveLocalTrack(
+            LocalTrack(
+                scannedTrack: scannedTrack,
+                observedAt: scannedAt
+            )
+        )
+
+        return .inserted
+    }
+
+    private func preferredTrack(
+        from tracks: [ScannedLocalTrack],
+        preferredPath: String?
+    ) -> ScannedLocalTrack {
+        if let preferredPath,
+           let matchingTrack = tracks.first(where: { $0.localFilePath == preferredPath })
+        {
+            return matchingTrack
+        }
+
+        return tracks.sorted { lhs, rhs in
+            lhs.localFilePath.localizedCaseInsensitiveCompare(rhs.localFilePath) == .orderedAscending
+        }.first ?? tracks[0]
+    }
+
+    private func mergedTrack(
+        _ existingTrack: LocalTrack,
+        with scannedTrack: ScannedLocalTrack,
+        scannedAt: Date
+    ) -> MergedTrack {
+        var updatedTrack = existingTrack
+        let wasDeleted = existingTrack.isDeleted
+        let didChange =
+            existingTrack.origin != .localScan
+            || existingTrack.title != scannedTrack.title
+            || existingTrack.artist != scannedTrack.artist
+            || existingTrack.album != scannedTrack.album
+            || existingTrack.durationSeconds != scannedTrack.durationSeconds
+            || existingTrack.localFilePath != scannedTrack.localFilePath
+            || existingTrack.sha256 != scannedTrack.sha256
+            || existingTrack.fileModifiedAt != scannedTrack.fileModifiedAt
+            || existingTrack.isDeleted
+
+        updatedTrack.origin = .localScan
+        updatedTrack.title = scannedTrack.title
+        updatedTrack.artist = scannedTrack.artist
+        updatedTrack.album = scannedTrack.album
+        updatedTrack.durationSeconds = scannedTrack.durationSeconds
+        updatedTrack.localFilePath = scannedTrack.localFilePath
+        updatedTrack.sha256 = scannedTrack.sha256
+        updatedTrack.fileModifiedAt = scannedTrack.fileModifiedAt
+        updatedTrack.lastScannedAt = scannedAt
+        updatedTrack.isDeleted = false
+        updatedTrack.deletedAt = nil
+
+        if didChange {
+            updatedTrack.updatedAt = scannedAt
+        }
+
+        return MergedTrack(
+            track: updatedTrack,
+            didChange: didChange,
+            wasDeleted: wasDeleted
+        )
+    }
+}
+
+private struct MergedTrack {
+    let track: LocalTrack
+    let didChange: Bool
+    let wasDeleted: Bool
+}
+
+private enum TrackResolution {
+    case inserted
+    case updated
+    case reactivated
+    case unchanged
+    case merged(additionalDeletedTrackCount: Int)
+    case mergedReactivated(additionalDeletedTrackCount: Int)
+}

packages/apple/VelodyPersistence/Sources/VelodyPersistence/LocalLibraryStore.swift

@@ -2,22 +2,6 @@ import Foundation
 import VelodyDomain
 
 public protocol LocalLibraryStore: Sendable {
-    func loadTracks() async -> [LibraryTrack]
-    func replaceTracks(_ tracks: [LibraryTrack]) async
-}
-
-public actor InMemoryLocalLibraryStore: LocalLibraryStore {
-    private var tracks: [LibraryTrack]
-
-    public init(tracks: [LibraryTrack] = []) {
-        self.tracks = tracks
-    }
-
-    public func loadTracks() async -> [LibraryTrack] {
-        tracks
-    }
-
-    public func replaceTracks(_ tracks: [LibraryTrack]) async {
-        self.tracks = tracks
-    }
+    func loadTracks() async throws -> [LibraryTrack]
+    func replaceTracks(_ tracks: [LibraryTrack]) async throws
 }

packages/apple/VelodyPersistence/Sources/VelodyPersistence/LocalMusicDiscovery.swift

@@ -31,5 +31,5 @@ public protocol MetadataReader {
 }
 
 public protocol LocalMusicScanner {
-    func scanFolder(at folderURL: URL) async throws -> [LibraryTrack]
+    func scanFolder(at folderURL: URL) async throws -> [ScannedLocalTrack]
 }

packages/apple/VelodyPersistence/Sources/VelodyPersistence/LocalTrackDTOs.swift

@@ -0,0 +1,204 @@
+import Foundation
+import VelodyDomain
+
+public enum LocalTrackOrigin: String, Codable, Hashable, Sendable {
+    case localScan
+    case syncBootstrap
+}
+
+public struct LocalTrack: Identifiable, Codable, Hashable, Sendable {
+    public var id: String
+    public var origin: LocalTrackOrigin
+    public var title: String
+    public var artist: String
+    public var album: String?
+    public var durationSeconds: Double?
+    public var localFilePath: String
+    public var sha256: String?
+    public var fileModifiedAt: Date?
+    public var lastScannedAt: Date?
+    public var isDeleted: Bool
+    public var deletedAt: Date?
+    public var createdAt: Date
+    public var updatedAt: Date
+
+    public init(
+        id: String,
+        origin: LocalTrackOrigin,
+        title: String,
+        artist: String,
+        album: String? = nil,
+        durationSeconds: Double? = nil,
+        localFilePath: String = "",
+        sha256: String? = nil,
+        fileModifiedAt: Date? = nil,
+        lastScannedAt: Date? = nil,
+        isDeleted: Bool = false,
+        deletedAt: Date? = nil,
+        createdAt: Date,
+        updatedAt: Date
+    ) {
+        self.id = id
+        self.origin = origin
+        self.title = title
+        self.artist = artist
+        self.album = album
+        self.durationSeconds = durationSeconds
+        self.localFilePath = localFilePath
+        self.sha256 = sha256
+        self.fileModifiedAt = fileModifiedAt
+        self.lastScannedAt = lastScannedAt
+        self.isDeleted = isDeleted
+        self.deletedAt = deletedAt
+        self.createdAt = createdAt
+        self.updatedAt = updatedAt
+    }
+
+    public init(
+        scannedTrack: ScannedLocalTrack,
+        id: String = UUID().uuidString,
+        observedAt: Date = Date()
+    ) {
+        self.init(
+            id: id,
+            origin: .localScan,
+            title: scannedTrack.title,
+            artist: scannedTrack.artist,
+            album: scannedTrack.album,
+            durationSeconds: scannedTrack.durationSeconds,
+            localFilePath: scannedTrack.localFilePath,
+            sha256: scannedTrack.sha256,
+            fileModifiedAt: scannedTrack.fileModifiedAt,
+            lastScannedAt: observedAt,
+            isDeleted: false,
+            deletedAt: nil,
+            createdAt: observedAt,
+            updatedAt: observedAt
+        )
+    }
+
+    public init(
+        libraryTrack: LibraryTrack,
+        origin: LocalTrackOrigin,
+        observedAt: Date = Date()
+    ) {
+        self.init(
+            id: libraryTrack.id,
+            origin: origin,
+            title: libraryTrack.title,
+            artist: libraryTrack.artist,
+            album: libraryTrack.album,
+            durationSeconds: libraryTrack.durationSeconds,
+            localFilePath: libraryTrack.localFilePath,
+            sha256: libraryTrack.sha256,
+            fileModifiedAt: nil,
+            lastScannedAt: origin == .localScan ? observedAt : nil,
+            isDeleted: false,
+            deletedAt: nil,
+            createdAt: observedAt,
+            updatedAt: observedAt
+        )
+    }
+
+    public var deduplicationKey: String {
+        Self.deduplicationKey(
+            origin: origin,
+            sha256: sha256,
+            id: id
+        )
+    }
+
+    public var libraryTrack: LibraryTrack {
+        LibraryTrack(
+            id: id,
+            title: title,
+            artist: artist,
+            album: album,
+            durationSeconds: durationSeconds,
+            localFilePath: localFilePath,
+            sha256: sha256
+        )
+    }
+
+    public static func deduplicationKey(
+        origin: LocalTrackOrigin,
+        sha256: String?,
+        id: String
+    ) -> String {
+        switch origin {
+        case .localScan:
+            if let sha256, !sha256.isEmpty {
+                return localScanDeduplicationKey(for: sha256)
+            }
+
+            return "localScan-id::\(id)"
+        case .syncBootstrap:
+            return "syncBootstrap-id::\(id)"
+        }
+    }
+
+    public static func localScanDeduplicationKey(for sha256: String) -> String {
+        "localScan::\(sha256)"
+    }
+}
+
+public struct ScannedLocalTrack: Identifiable, Hashable, Sendable {
+    public var id: String { localFilePath }
+    public var title: String
+    public var artist: String
+    public var album: String?
+    public var durationSeconds: Double?
+    public var localFilePath: String
+    public var sha256: String
+    public var fileModifiedAt: Date
+
+    public init(
+        title: String,
+        artist: String,
+        album: String? = nil,
+        durationSeconds: Double? = nil,
+        localFilePath: String,
+        sha256: String,
+        fileModifiedAt: Date
+    ) {
+        self.title = title
+        self.artist = artist
+        self.album = album
+        self.durationSeconds = durationSeconds
+        self.localFilePath = localFilePath
+        self.sha256 = sha256
+        self.fileModifiedAt = fileModifiedAt
+    }
+
+    public var deduplicationKey: String {
+        LocalTrack.localScanDeduplicationKey(for: sha256)
+    }
+}
+
+public struct LocalCatalogScanResult: Hashable, Sendable {
+    public var tracks: [LibraryTrack]
+    public var insertedTrackCount: Int
+    public var updatedTrackCount: Int
+    public var reactivatedTrackCount: Int
+    public var deletedTrackCount: Int
+    public var skippedDuplicateTrackCount: Int
+    public var unchangedTrackCount: Int
+
+    public init(
+        tracks: [LibraryTrack],
+        insertedTrackCount: Int,
+        updatedTrackCount: Int,
+        reactivatedTrackCount: Int,
+        deletedTrackCount: Int,
+        skippedDuplicateTrackCount: Int,
+        unchangedTrackCount: Int
+    ) {
+        self.tracks = tracks
+        self.insertedTrackCount = insertedTrackCount
+        self.updatedTrackCount = updatedTrackCount
+        self.reactivatedTrackCount = reactivatedTrackCount
+        self.deletedTrackCount = deletedTrackCount
+        self.skippedDuplicateTrackCount = skippedDuplicateTrackCount
+        self.unchangedTrackCount = unchangedTrackCount
+    }
+}

packages/apple/VelodyPersistence/Sources/VelodyPersistence/TrackEntity.swift

@@ -0,0 +1,76 @@
+import Foundation
+import SwiftData
+
+@Model
+final class TrackEntity {
+    @Attribute(.unique) var trackID: String
+    @Attribute(.unique) var deduplicationKey: String
+    var originRawValue: String
+    var title: String
+    var artist: String
+    var album: String?
+    var durationSeconds: Double?
+    var localFilePath: String
+    var sha256: String?
+    var fileModifiedAt: Date?
+    var lastScannedAt: Date?
+    var isMarkedDeleted: Bool
+    var deletedAt: Date?
+    var createdAt: Date
+    var updatedAt: Date
+
+    init(track: LocalTrack) {
+        trackID = track.id
+        deduplicationKey = track.deduplicationKey
+        originRawValue = track.origin.rawValue
+        title = track.title
+        artist = track.artist
+        album = track.album
+        durationSeconds = track.durationSeconds
+        localFilePath = track.localFilePath
+        sha256 = track.sha256
+        fileModifiedAt = track.fileModifiedAt
+        lastScannedAt = track.lastScannedAt
+        isMarkedDeleted = track.isDeleted
+        deletedAt = track.deletedAt
+        createdAt = track.createdAt
+        updatedAt = track.updatedAt
+    }
+
+    var localTrack: LocalTrack {
+        LocalTrack(
+            id: trackID,
+            origin: LocalTrackOrigin(rawValue: originRawValue) ?? .localScan,
+            title: title,
+            artist: artist,
+            album: album,
+            durationSeconds: durationSeconds,
+            localFilePath: localFilePath,
+            sha256: sha256,
+            fileModifiedAt: fileModifiedAt,
+            lastScannedAt: lastScannedAt,
+            isDeleted: isMarkedDeleted,
+            deletedAt: deletedAt,
+            createdAt: createdAt,
+            updatedAt: updatedAt
+        )
+    }
+
+    func apply(_ track: LocalTrack) {
+        trackID = track.id
+        deduplicationKey = track.deduplicationKey
+        originRawValue = track.origin.rawValue
+        title = track.title
+        artist = track.artist
+        album = track.album
+        durationSeconds = track.durationSeconds
+        localFilePath = track.localFilePath
+        sha256 = track.sha256
+        fileModifiedAt = track.fileModifiedAt
+        lastScannedAt = track.lastScannedAt
+        isMarkedDeleted = track.isDeleted
+        deletedAt = track.deletedAt
+        createdAt = track.createdAt
+        updatedAt = track.updatedAt
+    }
+}

packages/apple/VelodyPersistence/Sources/VelodyPersistence/TrackRepository.swift

@@ -0,0 +1,365 @@
+import Foundation
+@preconcurrency import SwiftData
+import VelodyDomain
+
+public protocol TrackRepository: LocalLibraryStore {
+    func loadLocalTracks(
+        origin: LocalTrackOrigin?,
+        includeDeleted: Bool
+    ) async throws -> [LocalTrack]
+    func findTrack(trackID: String) async throws -> LocalTrack?
+    func findTrack(deduplicationKey: String) async throws -> LocalTrack?
+    func findTrack(
+        localFilePath: String,
+        origin: LocalTrackOrigin?
+    ) async throws -> LocalTrack?
+    func saveLocalTrack(_ track: LocalTrack) async throws
+    func removeTracks(origin: LocalTrackOrigin?) async throws
+    func markDeletedLocalTracks(
+        missingFrom scannedFilePaths: Set<String>,
+        under rootFolderPath: String,
+        scannedAt: Date
+    ) async throws -> Int
+}
+
+public actor SwiftDataTrackRepository: TrackRepository {
+    private let modelContainer: ModelContainer
+    private let modelContext: ModelContext
+
+    public init(
+        databaseURL: URL? = nil,
+        isStoredInMemoryOnly: Bool = false,
+        fileManager: FileManager = .default
+    ) throws {
+        let configuration: ModelConfiguration
+
+        if isStoredInMemoryOnly {
+            configuration = ModelConfiguration(isStoredInMemoryOnly: true)
+        } else {
+            let storeURL: URL
+            if let databaseURL {
+                storeURL = databaseURL
+            } else {
+                storeURL = try Self.defaultStoreURL(fileManager: fileManager)
+            }
+            try fileManager.createDirectory(
+                at: storeURL.deletingLastPathComponent(),
+                withIntermediateDirectories: true
+            )
+            configuration = ModelConfiguration(url: storeURL)
+        }
+
+        modelContainer = try ModelContainer(
+            for: TrackEntity.self,
+            configurations: configuration
+        )
+        modelContext = ModelContext(modelContainer)
+        modelContext.autosaveEnabled = false
+    }
+
+    public func loadTracks() async throws -> [LibraryTrack] {
+        try await loadLocalTracks(origin: nil, includeDeleted: false)
+            .map(\.libraryTrack)
+    }
+
+    public func replaceTracks(_ tracks: [LibraryTrack]) async throws {
+        try await removeTracks(origin: .syncBootstrap)
+
+        let observedAt = Date()
+        for track in tracks {
+            try await saveLocalTrack(
+                LocalTrack(
+                    libraryTrack: track,
+                    origin: .syncBootstrap,
+                    observedAt: observedAt
+                )
+            )
+        }
+    }
+
+    public func loadLocalTracks(
+        origin: LocalTrackOrigin?,
+        includeDeleted: Bool
+    ) async throws -> [LocalTrack] {
+        try fetchEntities()
+            .map(\.localTrack)
+            .filter { track in
+                let originMatches = origin.map { track.origin == $0 } ?? true
+                let deletedMatches = includeDeleted || !track.isDeleted
+                return originMatches && deletedMatches
+            }
+            .sorted(by: sortTracks(_:_:))
+    }
+
+    public func findTrack(trackID: String) async throws -> LocalTrack? {
+        try fetchEntities()
+            .first(where: { $0.trackID == trackID })?
+            .localTrack
+    }
+
+    public func findTrack(deduplicationKey: String) async throws -> LocalTrack? {
+        try fetchEntities()
+            .first(where: { $0.deduplicationKey == deduplicationKey })?
+            .localTrack
+    }
+
+    public func findTrack(
+        localFilePath: String,
+        origin: LocalTrackOrigin?
+    ) async throws -> LocalTrack? {
+        let matches = try fetchEntities()
+            .map(\.localTrack)
+            .filter { track in
+                let pathMatches = track.localFilePath == localFilePath
+                let originMatches = origin.map { track.origin == $0 } ?? true
+                return pathMatches && originMatches
+            }
+            .sorted { lhs, rhs in
+                if lhs.isDeleted != rhs.isDeleted {
+                    return !lhs.isDeleted
+                }
+
+                return lhs.updatedAt > rhs.updatedAt
+            }
+
+        return matches.first
+    }
+
+    public func saveLocalTrack(_ track: LocalTrack) async throws {
+        let existingEntity = try findEntity(trackID: track.id)
+            ?? (try findEntity(deduplicationKey: track.deduplicationKey))
+
+        if let existingEntity {
+            existingEntity.apply(track)
+        } else {
+            modelContext.insert(TrackEntity(track: track))
+        }
+
+        try modelContext.save()
+    }
+
+    public func removeTracks(origin: LocalTrackOrigin?) async throws {
+        let matchingEntities = try fetchEntities().filter { entity in
+            guard let origin else {
+                return true
+            }
+
+            return entity.originRawValue == origin.rawValue
+        }
+
+        for entity in matchingEntities {
+            modelContext.delete(entity)
+        }
+
+        if !matchingEntities.isEmpty {
+            try modelContext.save()
+        }
+    }
+
+    public func markDeletedLocalTracks(
+        missingFrom scannedFilePaths: Set<String>,
+        under rootFolderPath: String,
+        scannedAt: Date
+    ) async throws -> Int {
+        let localTracks = try fetchEntities()
+            .filter { entity in
+                entity.originRawValue == LocalTrackOrigin.localScan.rawValue
+                    && !entity.isMarkedDeleted
+                    && isWithinRootFolder(entity.localFilePath, rootFolderPath: rootFolderPath)
+                    && !scannedFilePaths.contains(entity.localFilePath)
+            }
+
+        for entity in localTracks {
+            entity.isMarkedDeleted = true
+            entity.deletedAt = scannedAt
+            entity.lastScannedAt = scannedAt
+            entity.updatedAt = scannedAt
+        }
+
+        if !localTracks.isEmpty {
+            try modelContext.save()
+        }
+
+        return localTracks.count
+    }
+
+    private static func defaultStoreURL(fileManager: FileManager) throws -> URL {
+        guard let applicationSupportURL = fileManager.urls(
+            for: .applicationSupportDirectory,
+            in: .userDomainMask
+        ).first else {
+            throw CocoaError(.fileNoSuchFile)
+        }
+
+        return applicationSupportURL
+            .appendingPathComponent("Velody", isDirectory: true)
+            .appendingPathComponent("local-catalog.store")
+    }
+
+    private func fetchEntities() throws -> [TrackEntity] {
+        try modelContext.fetch(FetchDescriptor<TrackEntity>())
+    }
+
+    private func findEntity(trackID: String) throws -> TrackEntity? {
+        try fetchEntities().first(where: { $0.trackID == trackID })
+    }
+
+    private func findEntity(deduplicationKey: String) throws -> TrackEntity? {
+        try fetchEntities().first(where: { $0.deduplicationKey == deduplicationKey })
+    }
+
+}
+
+public actor InMemoryTrackRepository: TrackRepository {
+    private var tracksByDeduplicationKey: [String: LocalTrack]
+
+    public init(tracks: [LocalTrack] = []) {
+        tracksByDeduplicationKey = Dictionary(
+            uniqueKeysWithValues: tracks.map { ($0.deduplicationKey, $0) }
+        )
+    }
+
+    public func loadTracks() async throws -> [LibraryTrack] {
+        try await loadLocalTracks(origin: nil, includeDeleted: false)
+            .map(\.libraryTrack)
+    }
+
+    public func replaceTracks(_ tracks: [LibraryTrack]) async throws {
+        let retainedTracks = tracksByDeduplicationKey.values.filter { $0.origin != .syncBootstrap }
+        let observedAt = Date()
+        let replacementTracks = tracks.map {
+            LocalTrack(
+                libraryTrack: $0,
+                origin: .syncBootstrap,
+                observedAt: observedAt
+            )
+        }
+
+        tracksByDeduplicationKey = Dictionary(
+            uniqueKeysWithValues: (retainedTracks + replacementTracks).map {
+                ($0.deduplicationKey, $0)
+            }
+        )
+    }
+
+    public func loadLocalTracks(
+        origin: LocalTrackOrigin?,
+        includeDeleted: Bool
+    ) async throws -> [LocalTrack] {
+        tracksByDeduplicationKey.values
+            .filter { track in
+                let originMatches = origin.map { track.origin == $0 } ?? true
+                let deletedMatches = includeDeleted || !track.isDeleted
+                return originMatches && deletedMatches
+            }
+            .sorted(by: sortTracks(_:_:))
+    }
+
+    public func findTrack(trackID: String) async throws -> LocalTrack? {
+        tracksByDeduplicationKey.values.first(where: { $0.id == trackID })
+    }
+
+    public func findTrack(deduplicationKey: String) async throws -> LocalTrack? {
+        tracksByDeduplicationKey[deduplicationKey]
+    }
+
+    public func findTrack(
+        localFilePath: String,
+        origin: LocalTrackOrigin?
+    ) async throws -> LocalTrack? {
+        tracksByDeduplicationKey.values
+            .filter { track in
+                let pathMatches = track.localFilePath == localFilePath
+                let originMatches = origin.map { track.origin == $0 } ?? true
+                return pathMatches && originMatches
+            }
+            .sorted { lhs, rhs in
+                if lhs.isDeleted != rhs.isDeleted {
+                    return !lhs.isDeleted
+                }
+
+                return lhs.updatedAt > rhs.updatedAt
+            }
+            .first
+    }
+
+    public func saveLocalTrack(_ track: LocalTrack) async throws {
+        if let previousTrack = tracksByDeduplicationKey.values.first(where: { $0.id == track.id }),
+           previousTrack.deduplicationKey != track.deduplicationKey
+        {
+            tracksByDeduplicationKey.removeValue(forKey: previousTrack.deduplicationKey)
+        }
+
+        tracksByDeduplicationKey[track.deduplicationKey] = track
+    }
+
+    public func removeTracks(origin: LocalTrackOrigin?) async throws {
+        guard let origin else {
+            tracksByDeduplicationKey.removeAll()
+            return
+        }
+
+        tracksByDeduplicationKey = tracksByDeduplicationKey.filter { _, track in
+            track.origin != origin
+        }
+    }
+
+    public func markDeletedLocalTracks(
+        missingFrom scannedFilePaths: Set<String>,
+        under rootFolderPath: String,
+        scannedAt: Date
+    ) async throws -> Int {
+        var deletedTrackCount = 0
+
+        for track in tracksByDeduplicationKey.values where
+            track.origin == .localScan
+                && !track.isDeleted
+                && isWithinRootFolder(
+                    track.localFilePath,
+                    rootFolderPath: rootFolderPath
+                )
+                && !scannedFilePaths.contains(track.localFilePath)
+        {
+            var updatedTrack = track
+            updatedTrack.isDeleted = true
+            updatedTrack.deletedAt = scannedAt
+            updatedTrack.lastScannedAt = scannedAt
+            updatedTrack.updatedAt = scannedAt
+            tracksByDeduplicationKey[updatedTrack.deduplicationKey] = updatedTrack
+            deletedTrackCount += 1
+        }
+
+        return deletedTrackCount
+    }
+}
+
+public typealias InMemoryLocalLibraryStore = InMemoryTrackRepository
+
+private func sortTracks(_ lhs: LocalTrack, _ rhs: LocalTrack) -> Bool {
+    let titleOrder = lhs.title.localizedCaseInsensitiveCompare(rhs.title)
+    if titleOrder == .orderedSame {
+        let pathOrder = lhs.localFilePath.localizedCaseInsensitiveCompare(rhs.localFilePath)
+        if pathOrder == .orderedSame {
+            return lhs.id.localizedCaseInsensitiveCompare(rhs.id) == .orderedAscending
+        }
+
+        return pathOrder == .orderedAscending
+    }
+
+    return titleOrder == .orderedAscending
+}
+
+private func isWithinRootFolder(
+    _ filePath: String,
+    rootFolderPath: String
+) -> Bool {
+    let normalizedRoot = rootFolderPath.hasSuffix("/")
+        ? String(rootFolderPath.dropLast())
+        : rootFolderPath
+
+    if filePath == normalizedRoot {
+        return true
+    }
+
+    return filePath.hasPrefix(normalizedRoot + "/")
+}

packages/apple/VelodyPersistence/Tests/VelodyPersistenceTests/LocalCatalogServiceTests.swift

@@ -0,0 +1,273 @@
+import Foundation
+import XCTest
+@testable import VelodyPersistence
+import VelodyDomain
+
+final class LocalCatalogServiceTests: XCTestCase {
+    func testScanPersistsTracksAndSkipsDuplicateSHA() async throws {
+        let repository = try SwiftDataTrackRepository(isStoredInMemoryOnly: true)
+        let service = DefaultLocalCatalogService(repository: repository)
+        let modifiedAt = Date(timeIntervalSince1970: 1_000)
+
+        let result = try await service.reconcileScanResults(
+            [
+                makeScannedTrack(
+                    title: "Alpha",
+                    path: "/Music/Alpha.mp3",
+                    sha256: "sha-alpha",
+                    modifiedAt: modifiedAt
+                ),
+                makeScannedTrack(
+                    title: "Alpha Copy",
+                    path: "/Music/Copies/Alpha.mp3",
+                    sha256: "sha-alpha",
+                    modifiedAt: modifiedAt
+                ),
+            ],
+            in: URL(fileURLWithPath: "/Music"),
+            scannedAt: Date(timeIntervalSince1970: 1_100)
+        )
+
+        XCTAssertEqual(result.insertedTrackCount, 1)
+        XCTAssertEqual(result.skippedDuplicateTrackCount, 1)
+        XCTAssertEqual(result.deletedTrackCount, 0)
+        XCTAssertEqual(result.tracks.count, 1)
+        XCTAssertEqual(result.tracks.first?.localFilePath, "/Music/Alpha.mp3")
+
+        let storedTracks = try await repository.loadLocalTracks(
+            origin: .localScan,
+            includeDeleted: true
+        )
+        XCTAssertEqual(storedTracks.count, 1)
+        XCTAssertEqual(storedTracks.first?.sha256, "sha-alpha")
+        XCTAssertEqual(storedTracks.first?.fileModifiedAt, modifiedAt)
+    }
+
+    func testModifiedFileAtSamePathUpdatesExistingTrackInsteadOfDuplicating() async throws {
+        let repository = try SwiftDataTrackRepository(isStoredInMemoryOnly: true)
+        let service = DefaultLocalCatalogService(repository: repository)
+        let folderURL = URL(fileURLWithPath: "/Music")
+
+        _ = try await service.reconcileScanResults(
+            [
+                makeScannedTrack(
+                    title: "Original",
+                    path: "/Music/Track.mp3",
+                    sha256: "sha-original",
+                    modifiedAt: Date(timeIntervalSince1970: 2_000)
+                ),
+            ],
+            in: folderURL,
+            scannedAt: Date(timeIntervalSince1970: 2_100)
+        )
+
+        let result = try await service.reconcileScanResults(
+            [
+                makeScannedTrack(
+                    title: "Updated Title",
+                    path: "/Music/Track.mp3",
+                    sha256: "sha-updated",
+                    modifiedAt: Date(timeIntervalSince1970: 2_200)
+                ),
+            ],
+            in: folderURL,
+            scannedAt: Date(timeIntervalSince1970: 2_300)
+        )
+
+        XCTAssertEqual(result.insertedTrackCount, 0)
+        XCTAssertEqual(result.updatedTrackCount, 1)
+        XCTAssertEqual(result.deletedTrackCount, 0)
+        XCTAssertEqual(result.tracks.count, 1)
+        XCTAssertEqual(result.tracks.first?.title, "Updated Title")
+        XCTAssertEqual(result.tracks.first?.sha256, "sha-updated")
+
+        let storedTracks = try await repository.loadLocalTracks(
+            origin: .localScan,
+            includeDeleted: true
+        )
+        XCTAssertEqual(storedTracks.count, 1)
+        XCTAssertEqual(storedTracks.first?.title, "Updated Title")
+        XCTAssertEqual(storedTracks.first?.sha256, "sha-updated")
+    }
+
+    func testRescanMarksDeletedTracksAndReactivatesExistingSHA() async throws {
+        let repository = try SwiftDataTrackRepository(isStoredInMemoryOnly: true)
+        let service = DefaultLocalCatalogService(repository: repository)
+        let folderURL = URL(fileURLWithPath: "/Music")
+
+        _ = try await service.reconcileScanResults(
+            [
+                makeScannedTrack(
+                    title: "Alpha",
+                    path: "/Music/Alpha.mp3",
+                    sha256: "sha-alpha",
+                    modifiedAt: Date(timeIntervalSince1970: 3_000)
+                ),
+                makeScannedTrack(
+                    title: "Beta",
+                    path: "/Music/Beta.mp3",
+                    sha256: "sha-beta",
+                    modifiedAt: Date(timeIntervalSince1970: 3_000)
+                ),
+            ],
+            in: folderURL,
+            scannedAt: Date(timeIntervalSince1970: 3_100)
+        )
+
+        let deleteResult = try await service.reconcileScanResults(
+            [
+                makeScannedTrack(
+                    title: "Alpha",
+                    path: "/Music/Alpha.mp3",
+                    sha256: "sha-alpha",
+                    modifiedAt: Date(timeIntervalSince1970: 3_200)
+                ),
+            ],
+            in: folderURL,
+            scannedAt: Date(timeIntervalSince1970: 3_300)
+        )
+
+        XCTAssertEqual(deleteResult.deletedTrackCount, 1)
+        XCTAssertEqual(deleteResult.tracks.count, 1)
+
+        let reactivationResult = try await service.reconcileScanResults(
+            [
+                makeScannedTrack(
+                    title: "Alpha",
+                    path: "/Music/Alpha.mp3",
+                    sha256: "sha-alpha",
+                    modifiedAt: Date(timeIntervalSince1970: 3_400)
+                ),
+                makeScannedTrack(
+                    title: "Beta",
+                    path: "/Music/Recovered/Beta.mp3",
+                    sha256: "sha-beta",
+                    modifiedAt: Date(timeIntervalSince1970: 3_400)
+                ),
+            ],
+            in: folderURL,
+            scannedAt: Date(timeIntervalSince1970: 3_500)
+        )
+
+        XCTAssertEqual(reactivationResult.reactivatedTrackCount, 1)
+        XCTAssertEqual(reactivationResult.deletedTrackCount, 0)
+        XCTAssertEqual(reactivationResult.tracks.count, 2)
+
+        let storedTracks = try await repository.loadLocalTracks(
+            origin: .localScan,
+            includeDeleted: true
+        )
+        XCTAssertEqual(storedTracks.count, 2)
+        XCTAssertEqual(
+            storedTracks.first(where: { $0.sha256 == "sha-beta" })?.localFilePath,
+            "/Music/Recovered/Beta.mp3"
+        )
+        XCTAssertEqual(
+            storedTracks.first(where: { $0.sha256 == "sha-beta" })?.isDeleted,
+            false
+        )
+    }
+
+    func testRepositoryPersistsTracksAcrossInstances() async throws {
+        let fileManager = FileManager.default
+        let tempDirectory = fileManager.temporaryDirectory.appendingPathComponent(
+            UUID().uuidString,
+            isDirectory: true
+        )
+        let databaseURL = tempDirectory.appendingPathComponent("catalog.store")
+        let folderURL = URL(fileURLWithPath: "/Music")
+
+        defer {
+            try? fileManager.removeItem(at: tempDirectory)
+        }
+
+        let firstRepository = try SwiftDataTrackRepository(databaseURL: databaseURL)
+        let firstService = DefaultLocalCatalogService(repository: firstRepository)
+
+        _ = try await firstService.reconcileScanResults(
+            [
+                makeScannedTrack(
+                    title: "Persisted",
+                    path: "/Music/Persisted.mp3",
+                    sha256: "sha-persisted",
+                    modifiedAt: Date(timeIntervalSince1970: 4_000)
+                ),
+            ],
+            in: folderURL,
+            scannedAt: Date(timeIntervalSince1970: 4_100)
+        )
+
+        let secondRepository = try SwiftDataTrackRepository(databaseURL: databaseURL)
+        let storedTracks = try await secondRepository.loadLocalTracks(
+            origin: .localScan,
+            includeDeleted: false
+        )
+
+        XCTAssertEqual(storedTracks.count, 1)
+        XCTAssertEqual(storedTracks.first?.title, "Persisted")
+        XCTAssertEqual(storedTracks.first?.sha256, "sha-persisted")
+    }
+
+    func testSyncBootstrapReplacementLeavesLocalCatalogIntact() async throws {
+        let repository = try SwiftDataTrackRepository(isStoredInMemoryOnly: true)
+        let service = DefaultLocalCatalogService(repository: repository)
+
+        _ = try await service.reconcileScanResults(
+            [
+                makeScannedTrack(
+                    title: "Local Track",
+                    path: "/Music/Local.mp3",
+                    sha256: "sha-local",
+                    modifiedAt: Date(timeIntervalSince1970: 5_000)
+                ),
+            ],
+            in: URL(fileURLWithPath: "/Music"),
+            scannedAt: Date(timeIntervalSince1970: 5_100)
+        )
+
+        try await repository.replaceTracks(
+            [
+                LibraryTrack(
+                    id: "remote-track-1",
+                    title: "Remote Track",
+                    artist: "Remote Artist",
+                    album: "Remote Album",
+                    durationSeconds: 180,
+                    localFilePath: "",
+                    sha256: nil
+                ),
+            ]
+        )
+
+        let localTracks = try await repository.loadLocalTracks(
+            origin: .localScan,
+            includeDeleted: false
+        )
+        let remoteTracks = try await repository.loadLocalTracks(
+            origin: .syncBootstrap,
+            includeDeleted: false
+        )
+        let allTracks = try await repository.loadTracks()
+
+        XCTAssertEqual(localTracks.count, 1)
+        XCTAssertEqual(remoteTracks.count, 1)
+        XCTAssertEqual(allTracks.count, 2)
+    }
+
+    private func makeScannedTrack(
+        title: String,
+        path: String,
+        sha256: String,
+        modifiedAt: Date
+    ) -> ScannedLocalTrack {
+        ScannedLocalTrack(
+            title: title,
+            artist: "Artist",
+            album: "Album",
+            durationSeconds: 180,
+            localFilePath: path,
+            sha256: sha256,
+            fileModifiedAt: modifiedAt
+        )
+    }
+}

packages/apple/VelodySync/Sources/VelodySync/PlaceholderSyncCoordinator.swift

@@ -37,11 +37,12 @@ public actor PlaceholderSyncCoordinator: SyncCoordinator {
 
     public func performInitialSync() async throws -> SyncResult {
         let bootstrap = try await apiClient.fetchSyncBootstrap()
-        await store.replaceTracks(bootstrap.tracks)
+        try await store.replaceTracks(bootstrap.tracks)
+        let persistedTracks = try await store.loadTracks()
 
         return SyncResult(
-            statusMessage: "Sync bootstrap completed. Tracks: \(bootstrap.tracks.count). Next cursor: \(bootstrap.nextCursor.value).",
-            tracks: bootstrap.tracks,
+            statusMessage: "Sync bootstrap completed. Tracks: \(persistedTracks.count). Next cursor: \(bootstrap.nextCursor.value).",
+            tracks: persistedTracks,
             cursor: bootstrap.nextCursor
         )
     }