Offline, or when the page on screen isn't on the server yet, or when an
add waits unsent past the 5 s wait, "+" now copies the page as drawn on
this computer: a plain page add, then its items and lineup groups under
copy ids, queued in one write. The new page is served from that queued
work until its add lands, so it opens and takes edits offline and after
a restart. Online, the server still makes the copy.

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