CT_QR Banner

Displays a strip of QR codes at the bottom of the pack station screen,
so associates can scan them with their 2D scanner.

- Starts automatically when the user session opens and cannot be closed.
- Reserves its screen space: maximized windows stop above the banner.
- Never takes keyboard focus: the scanner keeps typing into the pack tool.
- No network access: the codes are shipped inside the package (codes.txt).
- Click a QR code to show it full size for 30 seconds.

Set the station number once with: ct-qr-banner.table 12