feat: Add playlist management functionality and compliance checks

- Introduced a new "Playlists" column in results view with visual indicators for membership.
- Added `playlist_api.py` to handle playlist-related operations (fetch, add, remove tracks).
- Implemented `PlaylistManagerDialog` for seamless playlist addition/removal with caching.
- Integrated compliance check script (`check_agents_compliance.py`) for ensuring coding standards.
- Added extensive documentation (`playlist_membership_manager.md`) covering architecture and flow.
- Updated GUI logic and QStandardItemModel setup to include playlist data.
- Included unit tests for playlist management components and API.

tidal_dl_ng/gui/main_window.py

@@ -19,6 +19,7 @@ from tidal_dl_ng.gui.downloads import DownloadsMixin
 from tidal_dl_ng.gui.history import HistoryMixin
 from tidal_dl_ng.gui.initialization import InitializationMixin
 from tidal_dl_ng.gui.playlist import GuiPlaylistManager
+from tidal_dl_ng.gui.playlist_membership_mixin import PlaylistMembershipMixin
 from tidal_dl_ng.gui.progress import ProgressMixin
 from tidal_dl_ng.gui.queue import GuiQueueManager
 from tidal_dl_ng.gui.search import GuiSearchManager
@@ -52,6 +53,7 @@ class MainWindow(
     TreesResultsMixin,
     ContextMenusMixin,
     HistoryMixin,
+    PlaylistMembershipMixin,
 ):
     """Main application window for TIDAL Downloader Next Generation.
 
@@ -169,7 +171,7 @@ class MainWindow(
 
         self.init_tidal(tidal)
 
-        logger_gui.debug("All setup.")
+        logger_gui.info("All setup.")
 
     def closeEvent(self, event: QtGui.QCloseEvent) -> None:
         """Handle the close event of the main window.
@@ -177,6 +179,12 @@ class MainWindow(
         Args:
             event (QtGui.QCloseEvent): The close event.
         """
+        logger_gui.warning("⚠️ CLOSE EVENT TRIGGERED!")
+        import traceback
+
+        logger_gui.debug("Close event traceback:")
+        for line in traceback.format_stack():
+            logger_gui.debug(line.strip())
         # Save the main window size and position
         self.settings.data.window_x = self.x()
         self.settings.data.window_y = self.y()