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/DataBackup/DataBackupSources.cs

@@ -8,4 +8,5 @@ namespace AIStudio.Tools.DataBackup;
 /// <param name="SettingsJson">The settings as the backup takes them along, cf. DataBackupSettings. They come from memory rather than from the disk, since the backup leaves out the objects of configuration plugins.</param>
 /// <param name="IndexCopiesDirectory">The copies of the indexes, in the layout of the data folder, or an empty string when the backup leaves the indexes out. The indexes in the data folder change while AI Studio runs, so the backup never reads them there.</param>
 /// <param name="OrganizationPluginFolders">The plugins an organization deployed among the user's own ones, cf. DataBackupContents.FindOrganizationPluginsAmongUserPlugins.</param>
-public sealed record DataBackupSources(string DataDirectory, string ConfigDirectory, string SettingsJson, string IndexCopiesDirectory, IReadOnlyList<string> OrganizationPluginFolders);
+/// <param name="CopyProvenanceStoreAsync">Copies the provenance store once the chats are written, and answers the directory of the copy, in the layout of the data folder, or an empty string when there is none. Copied after the chats, the store holds everything the chats of the backup refer to, also what an answer completed meanwhile received; what no chat of the backup refers to is removed after a restore. Without a copy, the backup takes the store from the data folder, which is consistent only while nothing writes to it, i.e., when AI Studio could not open the store at all.</param>
+public sealed record DataBackupSources(string DataDirectory, string ConfigDirectory, string SettingsJson, string IndexCopiesDirectory, IReadOnlyList<string> OrganizationPluginFolders, Func<CancellationToken, Task<string>>? CopyProvenanceStoreAsync = null);