This update makes the shared HTML building tools more flexible so they can be reused by the mass mailing app in a future refactoring. It moves useful design options into the common editor, improves configuration hooks, and fixes small reliability issues around editing behavior and placeholders.

This pull request makes small adjustments related to the `html_builder` in order to prepare for the `mass_mailing` refactoring.
See each specific commit for a contextualized explanation.

task-4247642

Co-authored-by: Damien Abeloos <abd@odoo.com>
Co-authored-by: Thomas Josse <thjo@odoo.com>

The scale certification screen now displays the Point of Sale version instead of the IoT device version. This gives users the relevant version information when checking certified scale status, reducing confusion during compliance or support checks.

We need to display the PoS Version, not the IoT version.

Forward-Port-Of: odoo/enterprise#91682

UAE payroll calculations now include days when an employee is outside their contract period. This helps payroll teams produce more accurate salary computations and reduces manual adjustments for contract start or end gaps.

days to UAE payroll

task-4700453

Forward-Port-Of: odoo/enterprise#84758

The Guatemalan EDI module now avoids heavy invoice-related recalculations during installation, reducing the risk of memory errors on large databases. It also no longer installs automatically with the base Guatemalan localization, giving businesses more control over when EDI is enabled.

This commit adds `_auto_init` to the `account.move` object in the Guatemalan EDI that prefills all computed stored fields in the move object with null values. This prevents computation on those fields when installing the module, and also prevents MemoryError on large databases.

task-5031330

Forward-Port-Of: odoo/enterprise#92881