Restore Zotero annotation sync for Zotero 7, 9, and 10: treat a successful Local API read as authoritative only when it actually contains annotation children, because the local children endpoint never returns annotation items, cross-check successful local reads without annotations against the Web API, the only source that exposes annotation children, keep fetches failure-safe: a Web answer completes the fetch even when empty, and incomplete fetches preserve the last good snapshot and cached annotation chunks.