Added the Model Comparison assistant for blind comparisons of two models (#1009)

Co-authored-by: Thorsten Sommer <SommerEngineering@users.noreply.github.com>

app/MindWork AI Studio/Chat/Embedded/EmbeddedChatOpening.cs

@@ -0,0 +1,22 @@
+namespace AIStudio.Chat.Embedded;
+
+/// <summary>
+/// Decides when an embedded chat sends the message it opens with, see EmbeddedChat.OpeningMessage.
+/// </summary>
+public static class EmbeddedChatOpening
+{
+    /// <summary>
+    /// Tells whether an embedded chat sends its opening message now.
+    /// </summary>
+    /// <remarks>
+    /// The message may arrive after the chat loaded, e.g., when the parent learns it only then: it is sent all the
+    /// same, as long as the user wrote nothing in the chat meanwhile. It is sent once per chat, also when sending
+    /// fails and it waits in the field instead.
+    /// </remarks>
+    /// <param name="openingMessage">The message the chat opens with, or null without one.</param>
+    /// <param name="conversation">The chat shown, or null while it loads.</param>
+    /// <param name="wasSent">Whether the chat sent its opening message already.</param>
+    /// <returns>True when the chat sends the message now.</returns>
+    public static bool SendsNow(ContentText? openingMessage, EmbeddedConversation? conversation, bool wasSent) =>
+        openingMessage is not null && !wasSent && conversation is { IsAvailable: true, IsRunning: false, UserMessageCount: 0 };
+}