chore: import upstream snapshot with attribution

examples/showcases/microsoft-kanban/agent/Program.cs

@@ -0,0 +1,133 @@
+using Microsoft.Agents.AI;
+using Microsoft.Agents.AI.AGUI;
+using Microsoft.Agents.AI.AGUI.Shared;
+using Microsoft.Agents.AI.Hosting.AGUI.AspNetCore;
+using Microsoft.AspNetCore.Http.Json;
+using Microsoft.Extensions.AI;
+using Microsoft.Extensions.Options;
+using OpenAI;
+using ProverbsAgent.Models;
+using ProverbsAgent.Services;
+using System.Text.Json.Serialization;
+
+var builder = WebApplication.CreateBuilder(args);
+
+builder.Services.ConfigureHttpJsonOptions(options =>
+{
+    options.SerializerOptions.TypeInfoResolverChain.Add(CanvasAgentSerializerContext.Default);
+});
+
+// Register AGUI services
+builder.Services.AddAGUI();
+
+var app = builder.Build();
+
+// Create the agent factory and map the AG-UI agent endpoint
+var jsonOptions = app.Services.GetRequiredService<IOptions<JsonOptions>>();
+var agentFactory = new CanvasAgentFactory(builder.Configuration, jsonOptions.Value.SerializerOptions);
+app.MapAGUI("/", agentFactory.CreateCanvasAgent());
+
+app.Run();
+
+// =================
+// Agent Factory
+// =================
+public class CanvasAgentFactory
+{
+    private readonly IConfiguration _configuration;
+    private readonly AgentState _state;
+    private readonly OpenAIClient _openAiClient;
+    private readonly System.Text.Json.JsonSerializerOptions _jsonSerializerOptions;
+
+    public CanvasAgentFactory(IConfiguration configuration, System.Text.Json.JsonSerializerOptions jsonSerializerOptions)
+    {
+        _configuration = configuration;
+        _jsonSerializerOptions = jsonSerializerOptions;
+
+        // Initialize with a default board matching frontend initialState
+        _state = new AgentState
+        {
+            Boards = new List<Board>
+            {
+                new Board
+                {
+                    Id = "board001",
+                    Name = "My First Board",
+                    Tasks = new List<KanbanTask>()
+                }
+            },
+            ActiveBoardId = "board001",
+            LastAction = ""
+        };
+
+        var openAiKey = _configuration["OpenAIKey"]
+            ?? throw new InvalidOperationException("OpenAIKey not found in configuration. Run: dotnet user-secrets set OpenAIKey \"YOUR_OPENAI_API_KEY\"");
+
+        _openAiClient = new OpenAIClient(openAiKey);
+    }
+
+    public AIAgent CreateCanvasAgent()
+    {
+        // Create Kanban service with shared state
+        var kanbanService = new KanbanService(_state);
+
+        var chatClient = _openAiClient.GetChatClient("gpt-4o-mini").AsIChatClient();
+
+        var chatClientAgent = chatClient.CreateAIAgent(
+            name: "my_agent",
+            instructions: @"A helpful assistant managing Kanban boards and tasks.
+
+You have tools to manage boards and tasks:
+- State: get_state (call this after modifications to see current state)
+- Board tools: create_board, delete_board, rename_board, switch_board
+- Task tools: create_task, update_task_field, add_task_tag, remove_task_tag, move_task_to_status, delete_task
+
+Each task has title, subtitle, description, tags[], and status.
+Tasks flow through 4 statuses: new → in_progress → review → completed.
+
+IMPORTANT: After creating or modifying boards/tasks, call get_state to retrieve the current state.",
+            tools: [
+                AIFunctionFactory.Create(kanbanService.GetState, new AIFunctionFactoryOptions { Name = "get_state", SerializerOptions = _jsonSerializerOptions }),
+                AIFunctionFactory.Create(kanbanService.CreateBoard, new AIFunctionFactoryOptions { Name = "create_board", SerializerOptions = _jsonSerializerOptions }),
+                AIFunctionFactory.Create(kanbanService.DeleteBoard, new AIFunctionFactoryOptions { Name = "delete_board", SerializerOptions = _jsonSerializerOptions }),
+                AIFunctionFactory.Create(kanbanService.SwitchBoard, new AIFunctionFactoryOptions { Name = "switch_board", SerializerOptions = _jsonSerializerOptions }),
+                AIFunctionFactory.Create(kanbanService.RenameBoard, new AIFunctionFactoryOptions { Name = "rename_board", SerializerOptions = _jsonSerializerOptions }),
+                AIFunctionFactory.Create(kanbanService.CreateTask, new AIFunctionFactoryOptions { Name = "create_task", SerializerOptions = _jsonSerializerOptions }),
+                AIFunctionFactory.Create(kanbanService.UpdateTaskField, new AIFunctionFactoryOptions { Name = "update_task_field", SerializerOptions = _jsonSerializerOptions }),
+                AIFunctionFactory.Create(kanbanService.AddTaskTag, new AIFunctionFactoryOptions { Name = "add_task_tag", SerializerOptions = _jsonSerializerOptions }),
+                AIFunctionFactory.Create(kanbanService.RemoveTaskTag, new AIFunctionFactoryOptions { Name = "remove_task_tag", SerializerOptions = _jsonSerializerOptions }),
+                AIFunctionFactory.Create(kanbanService.MoveTaskToStatus, new AIFunctionFactoryOptions { Name = "move_task_to_status", SerializerOptions = _jsonSerializerOptions }),
+                AIFunctionFactory.Create(kanbanService.DeleteTask, new AIFunctionFactoryOptions { Name = "delete_task", SerializerOptions = _jsonSerializerOptions })
+            ]
+        );
+
+        // Wrap with SharedStateAgent for AG-UI state synchronization
+        return new SharedStateAgent(chatClientAgent, _jsonSerializerOptions, _state);
+    }
+}
+
+public partial class Program { }
+
+// =================
+// State Snapshot
+// =================
+public class AgentStateSnapshot
+{
+    [JsonPropertyName("boards")]
+    public List<Board> Boards { get; set; } = new();
+
+    [JsonPropertyName("activeBoardId")]
+    public string ActiveBoardId { get; set; } = string.Empty;
+
+    [JsonPropertyName("lastAction")]
+    public string? LastAction { get; set; }
+}
+
+// =================
+// Serializer Context
+// =================
+[JsonSerializable(typeof(AgentStateSnapshot))]
+[JsonSerializable(typeof(Board))]
+[JsonSerializable(typeof(KanbanTask))]
+[JsonSerializable(typeof(AgentState))]
+internal sealed partial class CanvasAgentSerializerContext : JsonSerializerContext;