Astra's review of #368: copying whatever files the folder held let a
picture the original had already lost go unnoticed, and copied names the
file-name rule never checked. The duplicate now copies the files of the
pictures its pages and lineups show, named by imageFileName, and says how
many the original was already missing. It still duplicates: refusing would
leave copies older versions broke unduplicable for good.

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