Initial scaffold — NASBackup iOS app

Full project scaffold: XcodeGen project.yml, Core models/protocols/errors,
SMBService (kishikawakatsumi/SMBClient), SFTPService (Citadel 0.9.2),
PhotoLibraryService, LANMonitor, BackupEngine, BackgroundTaskManager,
all feature UIs (Login, Connect, Browse, Backup, History, Settings),
Shared components and theme. Builds clean with zero errors.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Core/Models/BackupJob.swift

@@ -0,0 +1,90 @@
+import Foundation
+import Combine
+
+enum BackupStatus: Equatable {
+    case idle
+    case preparing
+    case running
+    case paused
+    case completed
+    case failed(String)
+    case cancelled
+
+    var isActive: Bool {
+        switch self {
+        case .running, .paused, .preparing: return true
+        default: return false
+        }
+    }
+}
+
+@MainActor
+final class BackupJob: ObservableObject {
+    @Published private(set) var status: BackupStatus = .idle
+    @Published private(set) var totalFiles: Int = 0
+    @Published private(set) var uploadedFiles: Int = 0
+    @Published private(set) var skippedFiles: Int = 0
+    @Published private(set) var failedFiles: Int = 0
+    @Published private(set) var currentFileName: String = ""
+    @Published private(set) var currentFileSizeBytes: Int64 = 0
+    @Published private(set) var bytesTransferred: Int64 = 0
+    @Published private(set) var totalBytes: Int64 = 0
+    @Published private(set) var speedBytesPerSecond: Double = 0
+    @Published private(set) var startDate: Date?
+    @Published private(set) var endDate: Date?
+
+    var progress: Double {
+        guard totalFiles > 0 else { return 0 }
+        return Double(uploadedFiles + skippedFiles + failedFiles) / Double(totalFiles)
+    }
+
+    var eta: TimeInterval? {
+        guard speedBytesPerSecond > 0, totalBytes > bytesTransferred else { return nil }
+        return Double(totalBytes - bytesTransferred) / speedBytesPerSecond
+    }
+
+    func prepare() { status = .preparing }
+
+    func start(totalFiles: Int, totalBytes: Int64) {
+        self.totalFiles = totalFiles
+        self.totalBytes = totalBytes
+        self.uploadedFiles = 0
+        self.skippedFiles = 0
+        self.failedFiles = 0
+        self.bytesTransferred = 0
+        self.startDate = Date()
+        self.endDate = nil
+        self.status = .running
+    }
+
+    func updateProgress(fileName: String, fileSize: Int64, bytesTransferred: Int64, speed: Double) {
+        self.currentFileName = fileName
+        self.currentFileSizeBytes = fileSize
+        self.bytesTransferred = bytesTransferred
+        self.speedBytesPerSecond = speed
+    }
+
+    func fileCompleted(skipped: Bool = false) {
+        if skipped { skippedFiles += 1 } else { uploadedFiles += 1 }
+    }
+
+    func fileFailed() { failedFiles += 1 }
+
+    func finish(result: BackupResult) {
+        endDate = Date()
+        status = result.failedCount == 0 ? .completed : .completed
+    }
+
+    func fail(error: BackupError) {
+        endDate = Date()
+        status = .failed(error.errorDescription ?? error.localizedDescription)
+    }
+
+    func cancel() {
+        endDate = Date()
+        status = .cancelled
+    }
+
+    func pause() { if case .running = status { status = .paused } }
+    func resume() { if case .paused = status { status = .running } }
+}