Pull Request resolves #47282

• I read the Generative AI policy and my contribution is either not created with the help of AI or is compatible with the policy and GNU/GPL 2 or later.

Summary of Changes

Supersedes #47291 which was closed due to a rebase issue.
Adds support for the Reporting-Endpoints HTTP header in the System - HTTP Headers plugin.
Changes:

• Added reporting-endpoints to the list of supported HTTP headers.
• Added Reporting-Endpoints option to the plugin configuration dropdown.

Testing Instructions

1. Enable the System - HTTP Headers plugin.
2. In Force HTTP Headers, add a new header:
   • HTTP Header: Reporting-Endpoints
   • Value: default="https://example.com/report"
3. Check response headers.
   Example:
   curl -I http://localhost/joomla/

Actual result BEFORE applying this Pull Request

Reporting-Endpoints header cannot be configured through the plugin.

Expected result AFTER applying this Pull Request

Reporting-Endpoints header can be configured and appears in HTTP response.

Link to documentations

Please select:

• Documentation link for guide.joomla.org:

• No documentation changes for guide.joomla.org needed

• Pull Request link for manual.joomla.org:

• No documentation changes for manual.joomla.org needed