Once continuous scroll crosses a chapter boundary, the URL was stuck at
the originally-opened chapter so browser back / reload would jump the
user back there. Double-tap left/right also walked off the wrong chapter
since prevChapter/nextChapter were frozen at mount time.
- replaceState the URL as currentChapterNum changes (no server refetch).
- Derive prevChapter/nextChapter dynamically via useMemo on
currentChapterNum, dropping the now-redundant server-computed props.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
yiekheng
1c74348fae