product_variant_route_mto

Purpose

Allow marking specific product variants as Make To Order even when their template is not, while keeping consistency when the template is MTO.

Features

product.product: Adds an editable stored 'Variant is MTO' flag so a variant can be marked Make To Order independently of its template.
product.product: Keeps variant routes in sync with the template and automatically adds or removes MTO routes based on the variant flag, propagating non-MTO route changes back to the template.
product.product: Blocks disabling Make To Order on a variant when its template is MTO to avoid inconsistent routes.
product.template: Recomputes variant MTO flags when template routes change and warns that activating or deactivating an MTO route will reset variant settings.
product.product: Exposes the Variant is MTO toggle on the variant easy edit form.