add flashlight delegate to barcode reader base

@@ -7,12 +7,16 @@ import 'package:mobile_scanner/src/enums/mobile_scanner_error_code.dart';
 import 'package:mobile_scanner/src/mobile_scanner_exception.dart';
 import 'package:mobile_scanner/src/objects/barcode_capture.dart';
 import 'package:mobile_scanner/src/objects/start_options.dart';
+import 'package:mobile_scanner/src/web/flashlight_delegate.dart';
 import 'package:web/web.dart';
 
 /// This class represents the base interface for a barcode reader implementation.
 abstract class BarcodeReader {
   const BarcodeReader();
 
+  /// Get the flashlight delegate for the barcode reader.
+  FlashlightDelegate get flashlightDelegate => const FlashlightDelegate();
+
   /// Whether the scanner is currently scanning for barcodes.
   bool get isScanning {
     throw UnimplementedError('isScanning has not been implemented.');

@@ -7,6 +7,9 @@ import 'package:web/web.dart';
 ///
 /// It provides an interface to query and update the flashlight state of a [MediaStream].
 final class FlashlightDelegate {
+  /// Constructs a [FlashlightDelegate] instance.
+  const FlashlightDelegate();
+
   /// Returns a list of supported flashlight modes for the given [mediaStream].
   ///
   /// The [TorchState.off] mode is always supported, regardless of the return value.