CVE-2026-47228: Admidio's CSRF in registration `send_login` mode resets arbitrary user passwords

modules/registration.php mode send_login regenerates a random password for user_uuid_assigned, stores its bcrypt hash in adm_users.usr_password, and emails the cleartext to that user. Every other state-changing mode in the same file (assign_member, assign_user, delete_user, create_user) calls SecurityUtils::validateCsrfToken($_POST['adm_csrf_token']) first; the send_login branch does not. A page visited by a registration-administrator can issue the request as a top-level navigation, the browser sends the admin’s SameSite=Lax cookies, and the server resets the chosen user’s password without any further interaction from the admin.