Stock Picking Auto Create Package

This module adds automatic packing to transfers (receipts, deliveries, internal transfers).

On each operation type (for example "Delivery Orders") you get two new settings: an automatic package creation mode with the choices "Single Package" or "Per Smallest Packaging", and an option "requires packaging" that limits automatic packing to products that have packaging defined.

When a transfer is validated, all move lines that are not already in a package are packed automatically. In "Single Package" mode everything goes into one package. In "Per Smallest Packaging" mode the quantity is split into several packages, each holding the smallest packaging quantity of the product, and the move lines are split accordingly.

On a transfer that is ready (assigned), a new "Auto Pack" button appears next to Cancel so users can pack before validating. Lines already in a package, cancelled or done lines, and lines with no quantity are left untouched.

The module touches stock.picking, stock.picking.type and stock.move.line, and adds fields to the operation type form and a button to the transfer form.