Added the guided chat to the BeyondFacts Lab (#1177)

app/MindWork AI Studio/Assistants/BeyondFactsLab/BflConversation.cs

@@ -0,0 +1,38 @@
+using AIStudio.Chat;
+
+namespace AIStudio.Assistants.BeyondFactsLab;
+
+/// <summary>
+/// The chat of a step of the BeyondFacts Lab, as BflConversationService keeps it while the app runs.
+/// </summary>
+/// <remarks>
+/// The service keeps it beyond the page, so that an answer goes on while the person looks at another page, and the
+/// page shows it again when it comes back.
+/// </remarks>
+public sealed class BflConversation
+{
+    /// <summary>
+    /// Gets the step of the preparation the chat belongs to.
+    /// </summary>
+    public required BflThreadLocation Location { get; init; }
+
+    /// <summary>
+    /// Gets or sets the chat, or null when this version cannot open the stored one.
+    /// </summary>
+    public ChatThread? Thread { get; set; }
+
+    /// <summary>
+    /// Gets or sets whether the model answers right now.
+    /// </summary>
+    public bool IsRunning { get; set; }
+
+    /// <summary>
+    /// Gets whether the chat can be shown and continued.
+    /// </summary>
+    public bool IsAvailable => this.Thread is not null;
+
+    /// <summary>
+    /// Gets whether the chat has a message the person sees.
+    /// </summary>
+    public bool HasVisibleMessages => this.Thread?.Blocks.Any(block => !block.HideFromUser) ?? false;
+}