fixed shit with the renames

Views/ProgressWindow.xaml.cs

@@ -1,6 +1,7 @@
 using System.Collections.ObjectModel;
 using System.ComponentModel;
 using System.IO;
+using System.Text.RegularExpressions;
 using System.Windows;
 using Futonizer.Models;
 using Futonizer.Services;
@@ -110,6 +111,28 @@ public partial class ProgressWindow : FluentWindow
         TotalBytesText.Text = $"{doneMb:F0} / {totalMb:F0} MB copied";
     }
 
+    /// <summary>
+    /// If the source file's parent folder starts with a bracketed tag
+    /// (e.g. "[KAA]" or "[neoHEVC]") and the file name doesn't already
+    /// start with that tag, returns the file name with the tag prepended
+    /// (e.g. "[KAA] episode.mkv"). Otherwise returns the file name unchanged.
+    /// Only applied to the output file — the source is never touched.
+    /// </summary>
+    private static string PrefixedFileName(string sourceFilePath, string fileName)
+    {
+        string? folder = Path.GetDirectoryName(sourceFilePath);
+        if (string.IsNullOrEmpty(folder)) return fileName;
+
+        string folderName = Path.GetFileName(folder);
+        var match = Regex.Match(folderName, @"^\[.+?\]");
+        if (!match.Success) return fileName;
+
+        string prefix = match.Value + " "; // e.g. "[KAA] "
+        if (fileName.StartsWith(match.Value, StringComparison.Ordinal)) return fileName;
+
+        return prefix + fileName;
+    }
+
     private static long SafeFileLength(string path)
     {
         try { return new FileInfo(path).Length; }
@@ -159,7 +182,7 @@ public partial class ProgressWindow : FluentWindow
                 {
                     string outputFilePath = overwritingInPlace
                         ? file.FilePath
-                        : Path.Combine(_outputFolder, file.FileName);
+                        : Path.Combine(_outputFolder, PrefixedFileName(file.FilePath, file.FileName));
 
                     var videoIds = file.Tracks
                         .Where(t => t.Type == "video" && t.Copy)