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>

Features/Backup/BackupViewModel.swift

@@ -0,0 +1,19 @@
+import Foundation
+import Photos
+
+@MainActor
+final class BackupViewModel: ObservableObject {
+    @Published var totalPhotoCount: Int = 0
+    @Published var photosAuthStatus: PHAuthorizationStatus = PHPhotoLibrary.authorizationStatus(for: .readWrite)
+
+    private let photoService = PhotoLibraryService()
+
+    func loadPhotoCount(filter: BackupFilter) {
+        let assets = photoService.fetchAssets(filter: filter)
+        totalPhotoCount = assets.count
+    }
+
+    func requestPhotosAccess() async {
+        photosAuthStatus = await photoService.requestAuthorization()
+    }
+}