A queued page.add may name a page to copy. The server copies that
page's live items and lineups onto the new page, under copy ids that
keep their roots, in the same transaction that adds it, so the page
never appears without its content. A placed image still uploading is
left out; a page too large to copy refuses the add before anything is
written.

"Duplicate strategy" now copies through the same code (lib/contentCopy).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>