The maintenance "Fix alles" now has a checkbox to include or skip the
duplicate catalog_pages merge, so admins can choose whether to run it.
removeDuplicates takes an includePages flag and fixEverything threads it
through to the action.
The maintenance "Fix alles" now collapses catalog_pages that share the same
caption_save + parent_id into a single survivor (moving catalog_items and
reparenting child pages before deleting duplicates), so the catalog tree
never renders double links. The duplicate-page count is also surfaced in the
health panel.