Customers can now complete checkout for orders with a total of 0.00 without being asked to pay. Payment buttons are also hidden in emails when there is no amount due, reducing confusion for free orders such as event registrations.

... order and no mail with SO sent to the customer.
- Task: https://www.odoo.com/web?#id=9981&view_type=form&model=project.task&menu_id=3942&action=327
- Pad: https://pad.odoo.com/p/r.L3ViIukoIvlMwDc8

Event ticket quantities in the website shopping cart are now checked against available seats before checkout. This helps prevent customers from buying more tickets than are available and keeps attendee records in sync when cart quantities change.

- Task: https://www.odoo.com/web?#id=9971&view_type=form&model=project.task&menu_id=3942&action=327
- Pad: https://pad.odoo.com/p/r.BTJ9yFYnbxBG3VzQ