TanStack Query errored queries (staleTime: Infinity) are always stale — each
new observer subscription triggers a refetch regardless of retry:false.
RouteGuard mounting children on 401 caused continuous re-subscribe churn
(616+ requests in 15s confirmed by design-loop repro 2026-05-31).
Fix: on 401 in production, render NoAccessScreen variant="session" instead
of mounting the app subtree. Dev without Caddy keeps the passthrough
(process.env.NODE_ENV !== "production") so local next dev still works.
Also adds NoAccessScreen "session" variant (title: Сессия истекла,
subtitle: Обновите страницу, чтобы войти снова).
