This update reorganizes how sales order amounts are calculated so the logic is easier for developers to adapt and maintain. It should not change day-to-day sales workflows, but it helps reduce future customization effort and risk around order total calculations.

Description of the issue/feature this PR addresses:

Current behavior before PR:

Desired behavior after PR is merged:




---
I confirm I have signed the CLA and read the PR guidelines at www.odoo.com/submit-pr