feat: support web in package:platform

pkgs/platform/lib/platform.dart

@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 // Core interfaces & classes.
-export 'src/interface/local_platform.dart';
+export 'src/interface/local_platform.dart'
+    if (dart.library.js_interop) 'src/interface/local_platform_web.dart';
 export 'src/interface/platform.dart';
 export 'src/testing/fake_platform.dart';

pkgs/platform/lib/src/interface/local_platform_web.dart

@@ -0,0 +1,56 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'platform.dart';
+
+/// `Platform` implementation that .
+class LocalPlatform extends Platform {
+  /// Creates a new [LocalPlatform].
+  const LocalPlatform();
+
+  @override
+  int get numberOfProcessors => 0;
+
+  @override
+  String get pathSeparator => '/';
+
+  @override
+  String get operatingSystem => 'TODO'; // see web.window.navigator.platform
+
+  @override
+  String get operatingSystemVersion => 'TODO';
+
+  @override
+  String get localHostname => 'TODO';
+
+  @override
+  Map<String, String> get environment => {};
+
+  @override
+  String get executable => 'TODO';
+
+  @override
+  String get resolvedExecutable => 'TODO';
+
+  @override
+  Uri get script => Uri.base;
+
+  @override
+  List<String> get executableArguments => [];
+
+  @override
+  String? get packageConfig => 'TODO';
+
+  @override
+  String get version => 'TODO';
+
+  @override
+  bool get stdinSupportsAnsi => false;
+
+  @override
+  bool get stdoutSupportsAnsi => false;
+
+  @override
+  String get localeName => 'TODO';
+}