chore: import upstream snapshot with attribution

dotnet/samples/03-workflows/Agents/GroupChatToolApproval/DeploymentGroupChatManager.cs

@@ -0,0 +1,47 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using Microsoft.Agents.AI;
+using Microsoft.Agents.AI.Workflows;
+using Microsoft.Extensions.AI;
+
+namespace WorkflowGroupChatToolApprovalSample;
+
+/// <summary>
+/// Custom GroupChatManager that selects the next speaker based on the conversation flow.
+/// </summary>
+/// <remarks>
+/// This simple selector follows a predefined flow:
+/// 1. QA Engineer runs tests
+/// 2. DevOps Engineer checks staging and creates rollback plan
+/// 3. DevOps Engineer deploys to production (triggers approval)
+/// </remarks>
+internal sealed class DeploymentGroupChatManager : GroupChatManager
+{
+    private readonly IReadOnlyList<AIAgent> _agents;
+
+    public DeploymentGroupChatManager(IReadOnlyList<AIAgent> agents)
+    {
+        this._agents = agents;
+    }
+
+    protected override ValueTask<AIAgent> SelectNextAgentAsync(
+        IReadOnlyList<ChatMessage> history,
+        CancellationToken cancellationToken = default)
+    {
+        if (history.Count == 0)
+        {
+            throw new InvalidOperationException("Conversation is empty; cannot select next speaker.");
+        }
+
+        // First speaker after initial user message
+        if (this.IterationCount == 0)
+        {
+            AIAgent qaAgent = this._agents.First(a => a.Name == "QAEngineer");
+            return new ValueTask<AIAgent>(qaAgent);
+        }
+
+        // Subsequent speakers are DevOps Engineer
+        AIAgent devopsAgent = this._agents.First(a => a.Name == "DevOpsEngineer");
+        return new ValueTask<AIAgent>(devopsAgent);
+    }
+}