Page changes (add, rename, delete, reorder) now wait in the outbox as
records of their own, each with its place in the strategy's list, instead
of one record per page that a second change replaced. They are sent one at
a time in that order, renames ahead of anything that renumbers, and the
pages bar draws them over the server's pages until a read shows them.
Deleting the page on screen while the delete waits moves to another page.

Records an older build left keyed by page move into the list on start.

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