[Rom1-B]

Checklist before requesting a review

Please delete options that are not relevant.

• I have performed a self-review of my code.
• I have added tests (when available) that prove my fix is effective or that my feature works.
• I have updated the CHANGELOG with a short functional description of the fix or new feature.
• This change requires a documentation update.

Description

• It fixes !47188
• When the plugin is installed in a marketplace directory located outside the GLPI root (e.g. GLPI_MARKETPLACE_DIR set to /var/lib/glpi/marketplace), the login page requested its CSS and JS with the server filesystem path as URL.
• The files returned a 404, the alerts were unstyled and the server path was disclosed in the browser console.
• Assets are now loaded through the /plugins/news/ route, which works wherever the plugin is installed.

Refused to apply style from 'https://glpi.example.com/var/lib/glpi/marketplace/news/css/styles.css?v=...' because its MIME type ('text/html') is not a supported stylesheet MIME type, and strict MIME checking is enabled.
GET https://glpi.example.com/var/lib/glpi/marketplace/news/js/news.js?v=... net::ERR_ABORTED 404 (Not Found)

Screenshots (if appropriate):