fix: prevent internal server error by validating request body

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

AdminForth/1729/internal-server-error-when-i-m

Author: yaroslav8765

index.ts

@@ -72,7 +72,11 @@ export default class InlineCreatePlugin extends AdminForthPlugin {
       path: `/plugin/${this.pluginInstanceId}/create`,
       handler: async ({ body, adminUser }) => {
         const { record, resourceId } = body;
-        
+
+        if (!record) {
+          return { error: 'No record provided' };
+        }
+
         if ( this.resourceConfig.resourceId !== resourceId) {
           return { error: 'Resource ID mismatch' };
         }