The same skipEditCheck fix from 5dc9705294 but for the synced setting
handler, which updates lastRead when a lastRead setting arrives via
sync for a group attachment.
Track when attachments are last opened or read, storing a `lastRead` Unix timestamp on the attachment. For user library items, `lastRead` syncs as an attachment property in item JSON. For group library items, it syncs via a per-user synced setting (like `lastPageIndex`).
- Add `lastRead` column to `itemAttachments`
- Add `AttachmentReadObserver` to update `lastRead` on file open and page change (throttled to 5 min for page changes)
- Add "Recently Read" virtual collection (items read in last 14 days, sorted by `lastRead` descending)
- Add `lastRead` search condition with date operators
- Add `lastRead` item tree column with new `dependsOnChildren` property for parent item aggregation
- Add `getItemLastRead()` to return max `lastRead` across child attachments
Also:
- Generalize collection tree SCSS to support universal (context-fill) icons alongside themed icons
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Co-authored-by: Dan Stillman <dstillman@zotero.org>
