Add BotSharp.Plugin.Dify for hybrid workflow orchestration

src/Plugins/BotSharp.Plugin.Dify/BotSharp.Plugin.Dify.csproj

@@ -0,0 +1,17 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>$(TargetFramework)</TargetFramework>
+    <Nullable>enable</Nullable>
+    <LangVersion>$(LangVersion)</LangVersion>
+    <VersionPrefix>$(BotSharpVersion)</VersionPrefix>
+    <GeneratePackageOnBuild>$(GeneratePackageOnBuild)</GeneratePackageOnBuild>
+    <GenerateDocumentationFile>$(GenerateDocumentationFile)</GenerateDocumentationFile>
+    <OutputPath>$(SolutionDir)packages</OutputPath>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\Infrastructure\BotSharp.Core\BotSharp.Core.csproj" />
+  </ItemGroup>
+
+</Project>

src/Plugins/BotSharp.Plugin.Dify/DifyPlugin.cs

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+using BotSharp.Abstraction.Plugins;
+using BotSharp.Abstraction.Settings;
+using BotSharp.Plugin.Dify.Functions;
+using BotSharp.Plugin.Dify.HostedServices;
+using BotSharp.Plugin.Dify.Services;
+using BotSharp.Plugin.Dify.Settings;
+using Microsoft.Extensions.Configuration;
+
+namespace BotSharp.Plugin.Dify;
+
+/// <summary>
+/// Plugin for integrating BotSharp with Dify workflows
+/// This plugin enables BotSharp to act as a router/orchestrator
+/// while delegating workflow execution to Dify for flexible content generation
+/// </summary>
+public class DifyPlugin : IBotSharpPlugin
+{
+    public string Id => "f8a5c2d1-3e4b-4c5d-8f9a-1b2c3d4e5f6a";
+    public string Name => "Dify Workflow Integration";
+    public string Description => "Enables BotSharp to execute Dify workflows with async task polling support";
+    public string IconUrl => "https://docs.dify.ai/logo.png";
+
+    public SettingsMeta Settings => new SettingsMeta("Dify");
+
+    public object GetNewSettingsInstance() => new DifySettings();
+
+    public void RegisterDI(IServiceCollection services, IConfiguration config)
+    {
+        // Register settings
+        services.AddScoped(provider =>
+        {
+            var settingService = provider.GetRequiredService<ISettingService>();
+            return settingService.Bind<DifySettings>("Dify");
+        });
+
+        // Register services
+        services.AddScoped<DifyWorkflowService>();
+        services.AddSingleton<DifyTaskStorageService>();
+
+        // Register function callback
+        services.AddScoped<IFunctionCallback, CallDifyWorkflowFn>();
+
+        // Register background service for polling
+        services.AddHostedService<DifyTaskPollingService>();
+    }
+}