Rename ConversationDynamics to AgentConversation; add example test project and README

Co-authored-by: crickman <66376200+crickman@users.noreply.github.com>

dotnet/tests/AgentConversation.IntegrationTests/IConversationTestSystem.cs

@@ -0,0 +1,52 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Agents.AI;
+using Microsoft.Extensions.AI;
+
+namespace AgentConversation.IntegrationTests;
+
+/// <summary>
+/// Abstracts the system-specific concerns of an agent conversation test run: how agents are created
+/// and how context compaction is performed.
+/// </summary>
+/// <remarks>
+/// Implement this interface to adapt the <see cref="ConversationHarness"/> to a particular AI backend
+/// (e.g., OpenAI Chat Completion, Azure AI, OpenAI Responses API). Each implementation controls:
+/// <list type="bullet">
+/// <item><description>
+/// How <see cref="ConversationAgentDefinition"/> instances are turned into live <see cref="AIAgent"/> objects.
+/// </description></item>
+/// <item><description>
+/// How context compaction is applied to a list of messages. Compaction is optional; returning
+/// <see langword="null"/> means no compaction is performed.
+/// </description></item>
+/// </list>
+/// </remarks>
+public interface IConversationTestSystem
+{
+    /// <summary>
+    /// Creates a live <see cref="AIAgent"/> from the supplied <paramref name="definition"/>.
+    /// </summary>
+    /// <param name="definition">The definition describing the agent to create.</param>
+    /// <param name="cancellationToken">A token to cancel the operation.</param>
+    /// <returns>A fully-initialised <see cref="AIAgent"/> ready to participate in the conversation.</returns>
+    Task<AIAgent> CreateAgentAsync(
+        ConversationAgentDefinition definition,
+        CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Optionally compacts (reduces) the supplied <paramref name="messages"/>.
+    /// </summary>
+    /// <param name="messages">The current list of messages to compact.</param>
+    /// <param name="cancellationToken">A token to cancel the operation.</param>
+    /// <returns>
+    /// The compacted list of messages, or <see langword="null"/> if no compaction was performed.
+    /// When <see langword="null"/> is returned the original <paramref name="messages"/> list is used unchanged.
+    /// </returns>
+    Task<IList<ChatMessage>?> CompactAsync(
+        IList<ChatMessage> messages,
+        CancellationToken cancellationToken = default);
+}