type: fixed
area: subtitles

- Primary and secondary ASS subtitles now collapse layered and whitespace variants of full-span lyrics, including when playback starts or seeks into a line, reconstruct fragment-only karaoke per style, preserve authored stack order, keep canonical signs visible for their complete generated animation, navigate song lyrics by sanitized lines instead of generated animation events, and keep sidebar selections on the requested overlapping lyric while preserving unmatched dialogue and signs.