Scans every product in the catalog and classifies the NDC field.
Real NDCs are normalised to the standard 5-4-2 form.
Junk values (vendor codes, anything that isn't a real NDC) are moved
into the MPN field — or, if MPN already has a value, the NDC is
blanked and the row is flagged for staff review.
Preview shows what would change; nothing is written. Apply writes the changes and downloads the same report as Excel.