update content loading and error handling

unwind error handling

use auth cookie as source of truth, fetch config only when authenticated

src/util/auth.js

@@ -0,0 +1,8 @@
+// eslint-disable-next-line import/prefer-default-export
+export function isAuthenticated () {
+  const parsed = (`; ${document.cookie}`).split('; userLoggedIn=');
+  if (parsed.length === 2) {
+    return parsed.pop().split(';').shift() === 'true';
+  }
+  return false;
+}