This change adds support for configuring and switching between multiple websites. It also makes website menu configuration easier while hiding a confusing technical field from regular users, reducing mistakes in hosted environments.

Task: https://www.odoo.com/web?#id=21389&view_type=form&model=project.task&action=333&active_id=131&menu_id=4720
Pad: https://pad.odoo.com/p/r.xjbcD59szOZeLER9

 It enables
- the website switcher
- The "Configure website menus"

The online store now shows shoppers a clear warning in the cart when a selected product is unavailable. This helps prevent checkout frustration, reduces failed orders, and gives businesses better control over selling items that are out of stock.

Task : https://www.odoo.com/web?#id=11457&view_type=form&model=project.task&menu_id=3942&action=327
Pad:https://pad.odoo.com/p/r.hjHDaFRnr7QNH3LH

The contract revenue dashboard now includes cohort analysis to help teams track how customer groups perform over time. This gives business users clearer insight into revenue trends, retention, and contract performance for better decision-making.

Sales teams can mark stock moves as refunds so returned or refunded items reduce the delivered quantity on the related sales order. This makes it easier to create accurate refunds based on what was actually delivered and returned.

The commit adds a "Refund" field on the stock move, in the module
sale_stock. This allows to decrease the quantity delivered in the
associated SO, and therefore to generate refunds more easily.

The website selector is now hidden from the Website Configuration view because it was confusing for regular users and could cause issues in SaaS environments. The setting remains available where needed by the HTML editor, reducing accidental misconfiguration without removing underlying functionality.

Task: https://www.odoo.com/web#id=21389&view_type=form&model=project.task&menu_id=5200
Pad: https://pad.odoo.com/p/r.xjbcD59szOZeLER9

The Kanban view now avoids requesting extra field information when it is not needed. This reduces unnecessary data loading, helping screens open more efficiently without changing how users work.