A student logged into the CDP browser made gc_status answer "✅ Залогинен",
and every later read then ran silently as that student — returning that
user's view of the account instead of the admin's, with no error anywhere.

The check probed /teach/control, which renders a training list for students
too, so its "is this a training list?" test could never tell the roles apart.
It now probes /pl/user/user — the admin user list that gc_find_user and
resolveUserId already depend on — so a green status predicts that the rest
of the tools will actually work.

The wrong-role case is reported on its own, with the id and role GetCourse
prints in the page footer, instead of being collapsed into "not logged in".
The "denied" signal is anchored on GetCourse's error-page wording ("Возникла
ошибка #403", "отсутствуют права на это действие") rather than a loose "нет
доступа", which would false-positive on list content and lock an admin out.