Label switches from CODE128 to a QR encoding 'TAG|rev' (gage lab tag + latest
print-file revision), so a physical part carries which revision it was printed
from - short payload stays low-version + reliable at 0.5in (margin quiet zone,
EC M, no logo). Item exposes latestrevision; kiosk strips the |rev to resolve
and records the scanned revision on the take (migration 0004 adds
printeditemtransactions.revision) for traceability of which rev was consumed.
Manual entry records a null revision.