-Added step size selector to playback speed control.
-Added skip silence flag to player intents.
-Moved default preset in playback speed control to neutral dialog button, renamed as reset.
-Removed nightcore preset from playback speed control.
-Changed main video player to always self-destruct on stop.
-Extracted main video player lifecycle states into separate data class.
-Fixed play queue in full repeat mode does not load first item after expiring.