findIndex(t > now) - 1 returned -1 before the first line started, which the
`if (i < 0) i = lines.length - 1` guard turned into the LAST line — so playback
began scrolled to the bottom. Use a last-passed-index scan instead (-1 = before
the first line), centre the active line inside the box (so upcoming lyrics are
visible), and scroll the box itself rather than scrollIntoView(), which dragged
the whole page. Also bumps the box to 250px. Fixes yue2 post + both Suno posts.
Twelve Mandarin songs came back exactly 240.000 s with the outros cut.
Documents the ffprobe tell, the BPM myth, the seed-cache trap, the
2.0-2.8 hanzi/s spread, the 300 s VRAM ceiling, and the archive-the-clipped
policy. Ships 11 finished tracks with ASR-derived synced lyrics (EN + ZH).
hoelee