RELATE Vulnerable to Stored XSS via Unprivileged User Profile

RELATE is a web-based courseware package. Versions prior to commit 555f0efb1c5bd7531c07cd73724d7e566a81f620 have a stored cross-site scripting vulnerability that allows any enrolled student to execute arbitrary JavaScript in an administrator's browser session, potentially leading to full admin account takeover. The `get_user()` method in `ParticipationAdmin` renders user-controlled input using `mark_safe` combined with Python's % string formatting. This bypasses Django\'s automatic HTML escaping entirely. The value returned by `get_full_name` is derived directly from the `first_name` and `last_name` fields of the User model. These fields are freely editable by any authenticated user through the profile page (`/profile/`) with no sanitization applied. When an admin views the Participation list in the Django admin panel, the unsanitized value is rendered directly into the HTML response, causing the injected script to execute in the admin's browser. Commit 555f0efb1c5bd7531c07cd73724d7e566a81f620 fixes the issue.