Closes#4222.
Three changes that together stabilize Readest sync across devices:
**Stop the artificial updatedAt bump in useProgressAutoSave**
saveConfig unconditionally bumps config.updatedAt = Date.now(), and
useProgressAutoSave used to fire saveConfig on the very first relocate
after book open — even though that relocate just reflects the position
loaded from disk, not user action. The stale local config then looked
"newer" than a fresher server-side push, so the next auto-push
overwrote the other device's real progress via last-writer-wins. The
hook now snapshots the loaded location and skips saveConfig when the
in-memory location still matches it.
**Retry the first config pull with backoff + release the gate**
useProgressSync gates pushes behind a successful pull (so a brand-new
import can't clobber the server's real progress). But handleAutoSync
only re-arms on progress.location changes, so a single failed pull
(Android cold-start contention, Wi-Fi/LTE handoff, captive portal)
used to block every push for the whole reader session. The new
pullWithRetry retries on backoff (1500/4000/10000 ms) and releases
the gate after exhaustion — server-side last-writer-wins still
protects the cross-device case (a stale local push with an older
updated_at loses to a fresher server record). sync-book-progress
events reset the chain so manual pull-to-refresh recovers cleanly.
Fetch timeout bumped from 8s to 15s to better tolerate slow networks
in that cold-start window.
**Server piggybacks books.progress off configs push**
/api/sync POST now updates books.progress + books.updated_at for each
upserted config, gated by .lt('updated_at') so a concurrent newer
books push is never downgraded and a missing row is a silent no-op
(useBooksSync still seeds new rows from the library page). The
in-reader syncBooks round-trip is dropped — the reader now sends one
POST per auto-save instead of two, and the books row stays consistent
with config pushes even while a reader stays open (#4198).
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Huang Xin