fix: add customImageUrl to wordcloud config type

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/frameworks/components/configPanel/WordcloudConfig.tsx

@@ -47,6 +47,7 @@ export default function WordcloudConfig() {
     fontFamily: wc.fontFamily ?? 'sans-serif',
     fontWeight: wc.fontWeight ?? 'bold',
     colorMode: wc.colorMode ?? 'palette',
+    customImageUrl: wc.customImageUrl as string | undefined,
   };
 
   const update = useCallback(