Added a retrieval context validation agent (#289)

app/MindWork AI Studio/Agents/UserRequest.cs

@@ -0,0 +1,19 @@
+using AIStudio.Chat;
+
+namespace AIStudio.Agents;
+
+/// <summary>
+/// The created user request.
+/// </summary>
+public sealed class UserRequest
+{
+    /// <summary>
+    /// The time when the request was created.
+    /// </summary>
+    public required DateTimeOffset Time { get; init; }
+
+    /// <summary>
+    /// The user prompt.
+    /// </summary>
+    public required IContent UserPrompt { get; init; }
+}