MRP Serial Number Propagation (subcontracting)

This module makes the lot number propagation feature work with subcontracting manufacturing orders. When a manufacturing order is set to propagate a component's lot number to the finished product, the system automatically creates and assigns that propagated lot number when the subcontractor's components are recorded.

On the stock move lines (the detailed lines where lots/serials are entered), a new technical flag marks whether the lot field can still be edited. If the lot on the line matches the propagated lot of a subcontracting manufacturing order that has already been recorded, the lot field becomes read-only, so users cannot change it by mistake. This applies in the move line list, detailed list, form and operations views.

On the subcontracting manufacturing order form, the finished-product lot field is no longer mandatory when lot propagation is active, because the lot is filled in automatically instead of being typed by the user.

The module also tells the propagation logic that 'subcontract' bills of materials are eligible for lot number propagation, and it disables the 'assign serial number' button on moves when any of their lines has a locked lot.

It touches mrp.bom, mrp.production, stock.move and stock.move.line, and installs automatically alongside the subcontracting and lot propagation modules.