Product Packaging level purchasable

This module lets you decide which packagings are allowed on purchase orders. On each packaging level you get a new 'Can be purchased' checkbox (turned on by default), shown in the packaging level form and list views. Each packaging inherits this value from its packaging level, but you can still change it directly on the packaging itself.

When you build a purchase order, Odoo checks the packaging you pick on a purchase order line:

• If the packaging is not marked as purchasable, a warning message appears as soon as you select it.
• If you try to save the line anyway, Odoo raises a validation error naming the packaging and the product, and the line cannot be saved.
• When Odoo automatically suggests a packaging based on the product, quantity and unit of measure, it skips packagings that are not purchasable.

This affects the product.packaging.level, product.packaging and purchase.order.line models, so the rule applies to purchase orders created by users or generated automatically. It does not change sales, inventory or delivery flows.