Purchase landed costs - Alternative option

This module adds a new 'Costs distributions' area under the Purchase menu where you build a landed-cost document independently from the vendor bill. On the document you import the incoming shipments (receipts) you want to charge, then add expense lines such as transport, insurance or customs.

• Expense types are configured in their own menu: each type has a calculation method (by line amount, product price, quantity, weight, volume, or equally across lines), an optional default amount, and a 'default expense' flag so it is added automatically to every new distribution.
• You can restrict an expense to specific imported lines instead of all of them.
• A Calculate button spreads each expense over the lines using the chosen method and shows, per line, the previous cost, the unit cost added and the new cost; Set done confirms the distribution, Set draft reopens it.
• Expenses can be pulled from a posted supplier invoice line, converting the amount into the distribution currency, and from the vendor bill you can import the distributions linked to selected receipts.
• Deleting a confirmed distribution is blocked, and a cost line cannot be removed if an expense depends on it.

It touches purchase orders and receipts (buttons to open the related distributions), vendor bills (a 'Landed costs' tab), and product cost prices.