Bulk shelf scan

Shelf scan mode is for inventorying a whole shelf at once: tilt your phone along the labels and the app captures every barcode it sees.

1. Open the Scan tab and choose Shelf scan.
2. Hold the phone parallel to the labels and slowly pan across.
3. As barcodes are recognized, they appear in a stacked tray at the bottom.
4. Review the list and tap Save all to add or update inventory in one batch.

Screenshots for this workflow are captured manually from a device — the screen depends on the live camera, native barcode detection, and ARKit/ARCore anchors, none of which run inside flutter_test.