A reload in the middle of a drag (pointer still down) left the editor's
drag based on the old position: the next pointer move put back the drag
the reload had just undone, and when the dragged end was gone, the next
drag of another end started from its numbers. The editor now lets a drag
carry on only if the reload kept its end where the drag began.

fromHive sets the reopened edit in one assignment, so nothing watching
sees the edit end on the way.

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