Added file patterns and exclusions to folder data sources (#1057)

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

app/MindWork AI Studio/Tools/Services/DataSourceEmbeddingFilePatternGroup.cs

@@ -0,0 +1,10 @@
+namespace AIStudio.Tools.Services;
+
+/// <summary>
+/// Files outside the configured patterns, summarized by extension or by a known extensionless
+/// file type so a large folder does not put every deliberately excluded path into memory or the
+/// user interface.
+/// </summary>
+/// <param name="FileType">The normalized extension including its leading dot, a known extensionless filename, or an empty string for other files without an extension.</param>
+/// <param name="FileCount">How many files of this summarized type were found.</param>
+public sealed record DataSourceEmbeddingFilePatternGroup(string FileType, int FileCount);