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>

Tests/MockNASService.swift

@@ -34,6 +34,16 @@ final class MockNASService: NASTransferProtocol {
 
     func fileExists(at remotePath: String) async throws -> Bool { fileExistsAnswer }
 
+    func downloadData(at remotePath: String) async throws -> Data { Data() }
+
+    func writeData(_ data: Data, to remotePath: String) async throws {
+        if shouldFail { throw MockError.uploadFailed }
+    }
+
+    func deleteFile(at remotePath: String) async throws {
+        if shouldFail { throw MockError.uploadFailed }
+    }
+
     func upload(localURL: URL, remotePath: String, progress: @escaping (Int64, Int64) -> Void) async throws {
         if uploadDelay > 0 {
             try await Task.sleep(nanoseconds: UInt64(uploadDelay * 1_000_000_000))