Fix AppMenuView Connection Status UX and add smart sync dashboard

- Wi-Fi row: title always "Wi-Fi", subtitle shows SSID or Cellular/Not connected;
  badge is Connected (green) / Cellular (amber) / Offline (muted) — no more
  contradictory "No Wi-Fi" title with "Wi-Fi connected" subtitle
- NAS badge: Reachable now amber (TCP ping only, not auth-confirmed), Offline red,
  Unknown muted — removes misleading green on unverified NAS connectivity
- Error rows are now tappable; chevron affordance + ScaleButtonStyle; opens detail
  sheet with date, counts, duration, NAS host, trigger type, and suggested fix steps
- Sync Activity section: Clear button with confirmation alert (warns about error count
  if errors exist), calls store.clearHistory()
- BackupViewModel: compareWithNAS() computes accurate pre-scan alreadySafeCount /
  notBackedUpCount by matching lowercased filenames against NAS directory listing
- BackupView: ring shows state-based content (idle: not-backed-up count, running: %,
  completed: checkmark), pill-style page indicator, display counts update live during
  backup run, loadNASAndCompare() called on appear

Co-Authored-By: Kutesir <kutesir@provoc.ug>
Co-Authored-By: Sentry <sentry@provoc.ug>

Features/Backup/BackupViewModel.swift

@@ -4,13 +4,40 @@ import Photos
 @MainActor
 final class BackupViewModel: ObservableObject {
     @Published var totalPhotoCount: Int = 0
+    @Published var alreadySafeCount: Int = 0
+    @Published var notBackedUpCount: Int = 0
     @Published var photosAuthStatus: PHAuthorizationStatus = PHPhotoLibrary.authorizationStatus(for: .readWrite)
 
     private let photoService = PhotoLibraryService()
+    private var fetchedAssets: [PhotoAsset] = []
 
     func loadPhotoCount(filter: BackupFilter) {
         let assets = photoService.fetchAssets(filter: filter)
+        fetchedAssets = assets
         totalPhotoCount = assets.count
+        // Conservative initial state until NAS scan completes
+        alreadySafeCount = 0
+        notBackedUpCount = assets.count
+    }
+
+    // Called after NAS directory listing loads.
+    // Matches by lowercased filename — same heuristic BackupEngine uses for skip checks.
+    // This gives an accurate pre-scan "Already Safe / Not Backed Up" split before
+    // the user ever taps Start Backup.
+    func compareWithNAS(nasItems: [NASItem]) {
+        let nasFilenames = Set(
+            nasItems
+                .filter { !$0.isDirectory }
+                .map { $0.name.lowercased() }
+        )
+        var safe = 0
+        for asset in fetchedAssets {
+            if nasFilenames.contains(asset.filename.lowercased()) {
+                safe += 1
+            }
+        }
+        alreadySafeCount = safe
+        notBackedUpCount = totalPhotoCount - safe
     }
 
     func requestPhotosAccess() async {