Count the whole conversation against the model's window

app/MindWork AI Studio/Chat/PreparedSystemPrompt.cs

@@ -0,0 +1,19 @@
+namespace AIStudio.Chat;
+
+/// <summary>
+/// The system prompt of a chat thread as it would be sent, together with what building it decided.
+/// </summary>
+/// <remarks>
+/// The system prompt is not the text a person typed into it. A chat template may replace it, the
+/// retrieved data of a data source is appended to it, a profile adds its own paragraph, the tool
+/// policy adds another, and the current date goes in front of everything. Whoever wants to know how
+/// long the next request is has to ask the same question the request does.
+/// </remarks>
+/// <param name="Text">The whole system prompt, as the provider receives it.</param>
+/// <param name="BasePrompt">
+/// The prompt without any of the parts added around it. The thread keeps this one, so that it can
+/// still say which prompt it was configured with rather than the assembled result.
+/// </param>
+/// <param name="ProfileIsAllowed">Whether the chat template let a profile take part.</param>
+/// <param name="Explanation">What was used, in one sentence, for the log.</param>
+public sealed record PreparedSystemPrompt(string Text, string BasePrompt, bool ProfileIsAllowed, string Explanation);