This change adds the portal discussion area to customer-facing documents such as invoices and sales orders, so portal users can communicate and share files directly from those pages. It also fixes visibility and display issues in the portal chatter, making the experience more consistent and less confusing.

Description of the issue/feature this PR addresses:

Current behavior before PR:

Desired behavior after PR is merged:

task link -
https://www.odoo.com/web#id=37264&view_type=form&model=project.task&action=327&menu_id=

--
I confirm I have signed the CLA and read the PR guidelines at www.odoo.com/submit-pr

People with an upload share link can now submit files directly to document requests through public portal pages. This makes it easier to collect requested documents from external users without requiring extra account access or manual handling.

This merge implements the document request feature in
the portal (share link public pages). 

Task: #1894421