feat: add SDK command

puro/lib/src/cli.dart

@@ -19,6 +19,7 @@ import 'commands/flutter.dart';
 import 'commands/gc.dart';
 import 'commands/internal_generate_ast_parser.dart';
 import 'commands/internal_generate_docs.dart';
+import 'commands/locate_sdk.dart';
 import 'commands/ls_versions.dart';
 import 'commands/prefs.dart';
 import 'commands/pub.dart';
@@ -263,6 +264,7 @@ void main(List<String> args) async {
     ..addCommand(DartCommand())
     ..addCommand(PubCommand())
     ..addCommand(RunCommand())
+    ..addCommand(LocateSdkCommand())
     ..addCommand(GenerateDocsCommand())
     ..addCommand(GenerateASTParserCommand())
     ..addCommand(PuroUpgradeCommand())

puro/lib/src/commands/locate_sdk.dart

@@ -0,0 +1,34 @@
+import 'dart:async';
+
+import '../command.dart';
+import '../command_result.dart';
+import '../env/default.dart';
+import '../terminal.dart';
+
+class LocateSdkCommand extends PuroCommand {
+  @override
+  final name = 'sdk';
+
+  @override
+  // Command will be used by tools,
+  // so there's no way to react anyways
+  final allowUpdateCheck = false;
+
+  @override
+  final description = '''Prints the SDK path of the current environment.
+
+This can be used to configure vscode://settings/dart.getFlutterSdkCommand
+to automatically pick up the SDK of your puro environment.
+
+See https://github.com/Dart-Code/Dart-Code/pull/5377''';
+
+  @override
+  Future<CommandResult>? run() async {
+    final environment = await getProjectEnvOrDefault(scope: scope);
+    final path = environment.flutter.sdkDir.absolute.path;
+    return BasicMessageResult(
+      path,
+      type: CompletionType.plain,
+    );
+  }
+}