Changelog updates and check for sampling capability

Author: elliette

pkgs/dart_mcp/CHANGELOG.md

@@ -6,6 +6,7 @@
     been possible to use in a functional manner, so it is assumed that it had
     no usage previously.
 - Fix the `type` getter on `EmbeddedResource` to read the actual type field.
+- Add `toJson` method to the `CreateMessageResult` of a sampling request. 
 
 ## 0.4.0
 

pkgs/dart_mcp_server/CHANGELOG.md

@@ -10,7 +10,8 @@
   resources or resource links (when reading a directory).
 - Add `additionalProperties: false` to most schemas so they provide better
   errors when invoked with incorrect arguments.
-- Add `toJson` method to the `CreateMessageResult` of a sampling request. 
+- Add `DartMcpServer.samplingRequest` service extension method to send a sampling
+  request over DTD.
 
 # 0.1.1 (Dart SDK 3.10.0)
 

pkgs/dart_mcp_server/lib/src/mixins/dtd.dart

@@ -289,11 +289,13 @@ base mixin DartToolingDaemonSupport
   Future<void> _registerServices() async {
     final dtd = _dtd!;
 
-    await dtd.registerService(
-      McpServiceConstants.serviceName,
-      McpServiceConstants.samplingRequest,
-      _handleSamplingRequest,
-    );
+    if (clientCapabilities.sampling != null) {
+      await dtd.registerService(
+        McpServiceConstants.serviceName,
+        McpServiceConstants.samplingRequest,
+        _handleSamplingRequest,
+      );
+    }
   }
 
   Future<Map<String, Object?>> _handleSamplingRequest(Parameters params) async {