Update baseUrl in createStorybookDataSource to '/' for correct API endpoint

Author: hotlong

.storybook/datasource.ts

@@ -13,7 +13,7 @@ import { ObjectStackAdapter } from '@object-ui/data-objectstack';
  */
 export function createStorybookDataSource() {
   return new ObjectStackAdapter({
-    baseUrl: '',
+    baseUrl: '/',
     // No token needed for MSW
   });
 }