Added formulas from LaTeX code blocks and buttons to copy and save formulas (#1154)

app/MindWork AI Studio/Chat/MarkdownRenderPlan.cs

@@ -0,0 +1,12 @@
+namespace AIStudio.Chat;
+
+/// <summary>
+/// How the chat renders the text of a message: in parts, Markdown and the formulas between them, see
+/// MarkdownRenderPlanner.
+/// </summary>
+/// <param name="Source">The text as the chat renders it. The parts refer to it.</param>
+/// <param name="Segments">The parts, in the order of the text.</param>
+internal sealed record MarkdownRenderPlan(string Source, IReadOnlyList<MarkdownRenderSegment> Segments)
+{
+    public static readonly MarkdownRenderPlan EMPTY = new(string.Empty, []);
+}