Sale Order Line Packaging Quantity

This module extends sale order lines with a new "Package quantity" field, visible only to users who have the packaging feature enabled. It appears on the sale order form and in the order lines list, right next to the packaging selector.

• When a user picks a packaging on a line, the module automatically sets the package quantity to 1 and adjusts the ordered quantity to match one package. If the current ordered quantity is already an exact multiple of the package size, it keeps that quantity and shows the matching number of packages.
• Changing the package quantity recalculates the ordered quantity and unit of measure from the package size.
• The package quantity is computed automatically from the ordered quantity and the package size; if the ordered quantity is not an exact multiple of the package, the package quantity is shown as zero.
• Business rules: a package must be selected before entering a package quantity, and the package must have a quantity greater than zero; otherwise Odoo blocks the action with an error message.
• The packaging field becomes mandatory on the line as soon as a package quantity is entered.

The module touches sale.order.line and the sale order form view inherited from the sale stock module. It does not add menus, reports or scheduled jobs.