Fixed exports and the clipboard losing the sources of an answer (#966)

app/MindWork AI Studio/Tools/SourceExtensions.cs

@@ -153,6 +153,26 @@ public static partial class SourceExtensions
         return sb.ToString();
     }
 
+    /// <summary>
+    /// Converts a list of sources to a markdown-formatted string, headed by a title of its own.
+    /// </summary>
+    /// <remarks>
+    /// The chat shows the sources in a box below the answer, so the reader sees where the one ends
+    /// and the others begin. An exported document is one text: without a heading of its own, the
+    /// source list would read like one more section the model wrote. This is why the export asks
+    /// for this and the chat does not.
+    /// </remarks>
+    /// <param name="sources">The list of sources to convert.</param>
+    /// <returns>A markdown-formatted string representing the sources, or an empty string when there are none.</returns>
+    public static string ToExportMarkdown(this IList<Source> sources)
+    {
+        var sourcesMarkdown = sources.ToMarkdown();
+        if (string.IsNullOrWhiteSpace(sourcesMarkdown))
+            return string.Empty;
+
+        return $"# {TB("Sources")}{Environment.NewLine}{Environment.NewLine}{sourcesMarkdown}";
+    }
+
     /// <summary>
     /// Merges a list of added sources into an existing list of sources, avoiding duplicates based on normalized URLs.
     /// </summary>