Added a way to read what the AI received from your sources (#1100)

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

app/MindWork AI Studio/Tools/Databases/ProvenanceStore/ProvenanceEntry.cs

@@ -0,0 +1,16 @@
+namespace AIStudio.Tools.Databases.ProvenanceStore;
+
+/// <summary>
+/// One piece of content a chat received besides its messages, exactly as the AI received it.
+/// </summary>
+/// <remarks>
+/// Where the content comes from, such as the file, the page, or the tool, is kept by the chat
+/// itself, next to the id of this entry. The chat needs it to list its sources even without this
+/// store, and it would only be stored twice here.
+/// </remarks>
+/// <param name="Id">The id the chat refers to the entry by.</param>
+/// <param name="Kind">What sort of content this is.</param>
+/// <param name="Content">The content, after the prompt injection filter.</param>
+/// <param name="SurroundingContent">The content an ERI server sent along around its passage, empty for everything else.</param>
+/// <param name="CreatedAtUtc">When the entry was stored.</param>
+public sealed record ProvenanceEntry(Guid Id, ProvenanceKind Kind, string Content, IReadOnlyList<string> SurroundingContent, DateTimeOffset CreatedAtUtc);