forked from akai/readest
e1dad98e56
The TOC occasionally flashed a scroll to the current item and then
snapped back to the top, and on slow mobile first-opens sometimes
stayed at the top entirely.
Root cause: `useOverlayScrollbars({ defer: true })` schedules OS
construction via `requestIdleCallback` with a ~2233 ms timeout. On a
busy first open the timeout fires before the browser goes idle, so OS
wraps the viewport late — and the wrap step resets the scroller's
`scrollTop` synchronously, undoing Virtuoso's earlier scroll to the
current item. Virtuoso's `rangeChanged` / `onScroll` don't propagate
the reset for another frame, so any guard based on tracked scroll
state reads stale.