Make .NET CopilotClient.DisposeAsync graceful (#1932)

Author: SteveSandersonMS

dotnet/src/Client.cs

@@ -2444,13 +2444,15 @@ public void Dispose()
     /// </summary>
     /// <returns>A <see cref="ValueTask"/> representing the asynchronous dispose operation.</returns>
     /// <remarks>
-    /// This method calls <see cref="ForceStopAsync"/> to immediately release all resources.
+    /// This method calls <see cref="StopAsync"/> to gracefully shut down the runtime and
+    /// release all resources. Use <see cref="ForceStopAsync"/> for an immediate hard stop
+    /// that skips graceful runtime shutdown.
     /// </remarks>
     public async ValueTask DisposeAsync()
     {
         if (_disposed) return;
         _disposed = true;
-        await ForceStopAsync();
+        await StopAsync();
     }
 
     private class RpcHandler(CopilotClient client)

dotnet/test/Unit/ClientSessionLifetimeTests.cs

@@ -32,6 +32,20 @@ public async Task StopAsync_Requests_Runtime_Shutdown_For_Owned_Process()
         Assert.Equal(1, server.RuntimeShutdownCount);
     }
 
+    [Fact]
+    public async Task DisposeAsync_Requests_Runtime_Shutdown_For_Owned_Process()
+    {
+        await using var server = await FakeCopilotServer.StartAsync();
+        var client = new CopilotClient(new CopilotClientOptions { Connection = RuntimeConnection.ForUri(server.Url) });
+        await client.StartAsync();
+        using var process = StartExitedProcess();
+        await ReplaceConnectionCliProcessAsync(client, process);
+
+        await client.DisposeAsync();
+
+        Assert.Equal(1, server.RuntimeShutdownCount);
+    }
+
     [Fact]
     public async Task StopAsync_Does_Not_Throw_When_Runtime_Shutdown_Fails()
     {