Stock Available to Promise Release - Carrier Alternative

This module adds a new field on the delivery carrier form where you can select one or more alternative carriers. When a delivery order is released, Odoo checks the original carrier and its alternatives in sequence order and picks the first one whose conditions are met.

• On the delivery carrier screen, a new 'Alternative Carriers' field appears in the provider details section. You can add several carriers as tags.
• During the release of delivery operations, the system evaluates the current carrier and its alternatives. If a different carrier matches the picking, the delivery order is automatically updated to that carrier.
• The switch only happens if all moves on the picking still need to be released and none are cancelled. If only part of the moves are being released, the system splits the order into a backorder first.
• The module also ensures that when a new picking is created from a sale order line, the carrier defined on the procurement group is applied.
• It extends the procurement group to show its related delivery orders, and adjusts the processible quantity calculation to use the ordered available-to-promise quantity.

The changes affect delivery carriers, delivery orders, stock moves and procurement groups. No new menus or reports are added; the feature is integrated into existing delivery and inventory workflows.