Stock picking filter proucts

This module changes the product drop-down lists used in warehouse operations so that users can no longer choose products that are not physically available.

Where it applies: - On a transfer (stock picking) form, both in the detailed operations lines and in the operations without package lines, the product field is filtered. - On the scrap form, the product field is filtered the same way.

Business rule added: - A product is selectable only if it is a consumable, or if it has stock in a location that is the source location or one of its child locations. Products stored elsewhere are hidden from the list.

How it works behind the scenes: - Each product now carries a computed list of the locations where it currently has stock, based on its stock quantities. This list is stored and kept up to date automatically when stock moves change.

What it touches: - The product model (product.product) gains a Locations field. - The transfer form (stock.picking) and the scrap form (stock.scrap) are modified.

No new menus, reports, emails or scheduled actions are added. The change is purely a restriction on which products can be selected during picking and scrapping.