Fix tenant event form package selector so it no longer renders empty-value options, handles loading/empty

states, and pulls data from the authenticated /api/v1/tenant/packages endpoint.
    (resources/js/admin/pages/EventFormPage.tsx, resources/js/admin/api.ts)
  - Harden tenant-admin auth flow: prevent PKCE state loss, scope out StrictMode double-processing, add SPA
    routes for /event-admin/login and /event-admin/logout, and tighten token/session clearing semantics (resources/js/admin/auth/{context,tokens}.tsx, resources/js/admin/pages/{AuthCallbackPage,LogoutPage}.tsx,
    resources/js/admin/router.tsx, routes/web.php)

resources/js/admin/pages/AuthCallbackPage.tsx

@@ -8,8 +8,14 @@ export default function AuthCallbackPage() {
   const { completeLogin } = useAuth();
   const navigate = useNavigate();
   const [error, setError] = React.useState<string | null>(null);
+  const hasHandledRef = React.useRef(false);
 
   React.useEffect(() => {
+    if (hasHandledRef.current) {
+      return;
+    }
+    hasHandledRef.current = true;
+
     const params = new URLSearchParams(window.location.search);
     completeLogin(params)
       .then((redirectTo) => {