Send to chat (#77)

app/MindWork AI Studio/Chat/ChatThread.cs

@@ -3,7 +3,7 @@ namespace AIStudio.Chat;
 /// <summary>
 /// Data structure for a chat thread.
 /// </summary>
-public sealed class ChatThread
+public sealed record ChatThread
 {
     /// <summary>
     /// The unique identifier of the chat thread.

app/MindWork AI Studio/Chat/SystemPrompts.cs

@@ -0,0 +1,6 @@
+namespace AIStudio.Chat;
+
+public static class SystemPrompts
+{
+    public const string DEFAULT = "You are a helpful assistant!";
+}