get_current_active_user_from_websocket returns None after closing the socket
on an auth failure (revoked token, bad credentials, inactive user).
has_privilege_on_websocket dereferenced current_user.is_superadmin without a
None check, so any websocket auth failure surfaced as an AttributeError
traceback instead of a clean close. Bail out early when current_user is None,
mirroring the guard already present in ws_console.