Remove newFilesOnly toggle; add functional notifications; fix WiFi status

WHAT TO BACK UP section:
- Remove "New files only" / "Skip files already on NAS" toggle from Settings
- Remove BackupFilter.newFilesOnly field — duplicate protection is always active
  (fileExists pre-check + hybrid filterIndex ensure NAS files are never re-uploaded)

NOTIFICATIONS section:
- Replace static decorative rows with real ToggleRow controls backed by
  ConnectionStore (notifyOnStart=false, notifyOnComplete=true, notifyOnErrors=true)
- BackupEngine now gates notification calls behind these store flags

NETWORK section:
- WiFi row always shows ● On / ● Off indicator (was only shown when SSID known)
- Shows "Trusted" / "Unknown" when SSID is available, "On" / "Off" otherwise

Tests:
- makeAssets: add missing isScreenRecording parameter
- Rename test_backup_skipsExistingFiles_whenNewFilesOnly → _alwaysHardcoded,
  remove filter.newFilesOnly assignment
- MockNASService: add downloadData, writeData, deleteFile to satisfy protocol

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

Services/BackupEngine.swift

@@ -185,7 +185,9 @@ final class BackupEngine: ObservableObject {
 
         // ── 5. Upload loop ─────────────────────────────────────────────────
         job.start(totalFiles: pendingAssets.count, totalBytes: 0)
-        NotificationService.notifyBackupStarted(count: pendingAssets.count)
+        if store.notifyOnStart {
+            NotificationService.notifyBackupStarted(count: pendingAssets.count)
+        }
 
         // Build initial queue (all queued) for SyncView
         queueItems = pendingAssets.map { asset in
@@ -433,8 +435,10 @@ final class BackupEngine: ObservableObject {
 
         // Notifications
         if result.failedCount > 0 {
-            NotificationService.notifyBackupFailed(count: result.failedCount)
-        } else {
+            if store.notifyOnErrors {
+                NotificationService.notifyBackupFailed(count: result.failedCount)
+            }
+        } else if store.notifyOnComplete {
             NotificationService.notifyBackupCompleted(
                 uploaded: result.uploadedCount,
                 total: BackupStatusService.shared.snapshot.phoneTotal