Engagements store partial dates as value + precision and track field_sources;
lists (list/grouping/thread, grouping-only rating/review) keep dense item
order and snapshot items in history; copies store price in cents. All three
restore through restoreVersion.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Entries carry per-field field_sources, write user_history diffs, resolve
aliased/merged works, and support quick add, per-user moves (with alias and
draft tombstone) and keyset-paginated library listing with child rollups.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
