add guard for reg-only pages

src/ez_lan_manager/helpers/LoggedInGuard.py

@@ -0,0 +1,10 @@
+from typing import Optional
+
+from rio import Session, URL
+
+from src.ez_lan_manager.types.SessionStorage import SessionStorage
+
+
+def logged_in_guard(session: Session, _) -> Optional[URL]:
+    if session[SessionStorage].user_id is None:
+        return URL("./")