chore: import upstream snapshot with attribution

dotnet/samples/02-agents/DevUI/README.md

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+# DevUI Samples
+
+This folder contains samples demonstrating how to use the DevUI in ASP.NET Core applications.
+
+## What is DevUI?
+
+The DevUI provides an interactive web interface for testing and debugging AI agents during development.
+
+## Samples
+
+### [DevUI_Step01_BasicUsage](./DevUI_Step01_BasicUsage)
+
+Shows how to add DevUI to an ASP.NET Core application with multiple agents and workflows.
+
+**Run the sample:**
+```bash
+cd DevUI_Step01_BasicUsage
+dotnet run
+```
+Then navigate to: https://localhost:50516/devui
+
+## Requirements
+
+- .NET 8.0 or later
+- ASP.NET Core
+- Azure OpenAI credentials
+
+## Quick Start
+
+To add DevUI to your application:
+
+```csharp
+var builder = WebApplication.CreateBuilder(args);
+
+// Set up the chat client
+builder.Services.AddChatClient(chatClient);
+
+// Register your agents
+builder.AddAIAgent("my-agent", "You are a helpful assistant.");
+
+// Register services for OpenAI responses and conversations (also required for DevUI)
+builder.Services.AddOpenAIResponses();
+builder.Services.AddOpenAIConversations();
+
+var app = builder.Build();
+
+// Map endpoints for OpenAI responses and conversations (also required for DevUI)
+app.MapOpenAIResponses();
+app.MapOpenAIConversations();
+
+if (builder.Environment.IsDevelopment())
+{
+    // Map DevUI endpoint to /devui
+    app.MapDevUI();
+}
+
+app.Run();
+```
+
+Then navigate to `/devui` in your browser.