Fix box numbers that skip after deleting a box

Delete a box to return its panels to the un-packed pool, then reassign annotations so the remaining boxes are renamed sequentially.

1. When a box is created on the Packaging page without a custom name, it is auto-named 'Box N' based on the boxes currently on the work order.

   ✓ Checked in the product on 9 October 2026

2. Deleting a box returns all its panels to the un-packed pool (their packaging record is cleared) and removes the box's hardware lines — the panels do NOT need to be individually removed first.

   ✓ Checked in the product on 9 October 2026

3. Deleting a box that was already loaded onto a shipment also removes it from the loaded counts and updates the shipment's status, so progress can drop after a deletion.

4. A box in a shipment that has already been dispatched cannot be deleted.

5. The box list can be reassigned (Reassign Annotations) so boxes are renamed sequentially in creation order.

6. Reassigning annotations renames boxes sequentially in creation order, so a gap such as 'Box 5' when only three boxes exist is corrected.

7. Boxes that are already in a dispatched shipment keep their printed names, so their labels stay unambiguous.