Implemented hot restart over websocket (#2666)

* implemented hot restart over websocket

* remove service callback for fullReload

* addressed comments

* addressed comments

Author: jyameo

dwds/CHANGELOG.md

@@ -1,5 +1,7 @@
 ## 24.4.2-wip
 
+- Implemented hot restart over websockets with multi window support.
+- Fix refresh race condition bug by adding an isolate destruction grace period.
 - Update a call to the `package:shelf_web_socket` `webSocketHandler()` function.
 
 ## 24.4.1

dwds/lib/data/hot_restart_request.dart

@@ -0,0 +1,24 @@
+// Copyright (c) 2025, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library hot_restart_request;
+
+import 'package:built_value/built_value.dart';
+import 'package:built_value/serializer.dart';
+
+part 'hot_restart_request.g.dart';
+
+/// A request to hot restart the application.
+abstract class HotRestartRequest
+    implements Built<HotRestartRequest, HotRestartRequestBuilder> {
+  static Serializer<HotRestartRequest> get serializer =>
+      _$hotRestartRequestSerializer;
+
+  /// A unique identifier for this request.
+  String get id;
+
+  HotRestartRequest._();
+  factory HotRestartRequest([void Function(HotRestartRequestBuilder) updates]) =
+      _$HotRestartRequest;
+}

dwds/lib/data/hot_restart_request.g.dart

@@ -0,0 +1,32 @@
+// Copyright (c) 2025, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library hot_restart_response;
+
+import 'package:built_value/built_value.dart';
+import 'package:built_value/serializer.dart';
+
+part 'hot_restart_response.g.dart';
+
+/// A response to a hot restart request.
+abstract class HotRestartResponse
+    implements Built<HotRestartResponse, HotRestartResponseBuilder> {
+  static Serializer<HotRestartResponse> get serializer =>
+      _$hotRestartResponseSerializer;
+
+  /// The unique identifier matching the request.
+  String get id;
+
+  /// Whether the hot restart succeeded on the client.
+  bool get success;
+
+  /// An optional error message if success is false.
+  @BuiltValueField(wireName: 'error')
+  String? get errorMessage;
+
+  HotRestartResponse._();
+  factory HotRestartResponse([
+    void Function(HotRestartResponseBuilder) updates,
+  ]) = _$HotRestartResponse;
+}