Set default channel value for webchat.

src/Infrastructure/BotSharp.Abstraction/Conversations/Models/IncomingMessageModel.cs

@@ -1,9 +1,7 @@
-using BotSharp.Abstraction.Models;
-
 namespace BotSharp.Abstraction.Conversations.Models;
 
 public class IncomingMessageModel : MessageConfig
 {
     public string Text { get; set; } = string.Empty;
-    public virtual string Channel { get; set; }
+    public virtual string Channel { get; set; } = string.Empty;
 }

src/Plugins/BotSharp.Plugin.ChatbotUI/ChatbotUiController.cs

@@ -78,7 +78,7 @@ public class ChatbotUiController : ControllerBase, IApiAdapter
         conv.SetConversationId(input.ConversationId, input.States);
         conv.States.SetState("provider", input.Provider)
             .SetState("model", input.Model)
-            .SetState("channel", "webchat")
+            .SetState("channel", input.Channel)
             .SetState("temperature", input.Temperature)
             .SetState("sampling_factor", input.SamplingFactor);
 

src/Plugins/BotSharp.Plugin.ChatbotUI/ViewModels/OpenAiMessageInput.cs

@@ -9,6 +9,7 @@ public class OpenAiMessageInput : IncomingMessageModel
 {
     public string AgentId { get; set; } = string.Empty;
     public string ConversationId { get; set; } = string.Empty;
+    public override string Channel { get; set; } = "webchat";
 
     public List<OpenAiMessageBody> Messages { get; set; } = new List<OpenAiMessageBody>();