load playlist in separate thread to prevent blocking on startup

utils/radio_util.py

@@ -57,6 +57,7 @@ class RadioUtil:
             "electronic",
         ]
         self.active_playlist: list[dict] = []
+        self.playlist_loaded: bool = False
         self.now_playing: dict = {
             "artist": "N/A",
             "song": "N/A",
@@ -378,6 +379,7 @@ class RadioUtil:
                             "%s items remain for playback after filtering",
                             len(self.active_playlist),
                         )
+                self.playlist_loaded = True
         except Exception as e:
             logging.info("Playlist load failed: %s", str(e))
             traceback.print_exc()