The sync POST handler rewrote books.updated_at = now() whenever a pushed
book's resolved reading_status differed from the server row's. A book that
was imported locally and never given a status sends reading_status:
undefined, while the server stores null, so `undefined !== null` reported a
spurious status change. The 1-day re-sync window re-pushes every recently
touched book on each sync, so the server stamped those books with a fresh,
batch-identical timestamp every cycle, floating them to the top of the
date-sorted library (and above a book the user had just read).
Normalize nullish reading_status values before comparing so a statusless
book never registers as a status change. Verified on-device via CDP:
PUSH_SENT carried the old timestamp while PUSH_RETURNED came back with a
fresh now() for exactly the statusless books.
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Huang Xin
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