The multilingual accounting localization module has been reorganized and migrated to Odoo's newer internal framework. This should make the module easier to maintain and align it with current platform standards, with limited direct impact on daily users.

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This update reorganizes the French FEC accounting export module and migrates it to Odoo's newer internal application framework. For business users, the change should help keep French accounting compliance reporting maintainable and aligned with the current Odoo platform, without introducing a major functional change.

Description of the issue/feature this PR addresses:

Current behavior before PR:

Desired behavior after PR is merged:
## 

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The EU service tax localization module has been reorganized and migrated to Odoo's newer application framework. This helps keep the module maintainable and compatible with current Odoo development standards, with limited direct impact on day-to-day users.

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

The stock landed costs module was updated to use Odoo's newer internal framework, making it easier to maintain and evolve. Existing landed cost features and related tests were migrated without introducing a new business workflow.

<strong>Task:</strong> https://www.odoo.com/web#id=13132&view_type=form&model=project.task&menu_id=3942&action=327
<strong>Pad:</strong> https://pad.odoo.com/p/r.dTbdXwkcpfrYp0Ww