This update introduces a new AI app that lets businesses create AI assistants able to answer questions using uploaded documents or web pages. It also adds calendar integration so these assistants can help schedule meetings, providing an early foundation for AI-driven productivity inside Odoo.

This PR is a follow-up on the implementation of the new AI features.

It backports the new AI app that introduce two new modules `ai` and `ai_calendar`, as well as a few fixes for these modules.

Community PR: https://github.com/odoo/odoo/pull/208284