A done chapter after the head now counts as left again when it was finished
more than rereadDays before the head (default 7) or before a run of more
than rereadChapters chapters read in order up to the head (default 5).
Both are user settings under Library page; 0 turns a rule off.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>