The marketing campaign app was modernized internally and reorganized to make it easier to maintain. Existing campaign behavior should remain the same, with improved reliability around tests, diagram views, and campaign segment handling.

Task: https://www.odoo.com/web#id=12168&view_type=form&model=project.task&menu_id=3942&action=327

Pad: https://pad.odoo.com/p/r.gx6zwHpL0iaRYqhv