Added "Custom Sorting" to playlist view.

wobuzz/player/playlist.py

@@ -1,6 +1,7 @@
 #!/usr/bin/python3
 
 import os
+from PyQt6.QtCore import Qt
 from .track import Track
 
 
@@ -8,6 +9,7 @@ class Playlist:
     def __init__(self, app, title: str):
         self.app = app
         self.title = title  # playlist title
+        self.sorting: list[Qt.SortOrder] | None = None  # Custom sort order if None
         self.tracks: list[Track] = []
         self.current_track_index = 0
         self.current_track: Track | None = None