polling cap and null check

Author: rugeli

src/cms/widgets/CloudinaryImageWidget.tsx

@@ -204,12 +204,19 @@ const CloudinaryImageWidget: React.FC<CloudinaryWidgetProps> = ({
         if (src && !src.endsWith("undefined")) {
             setLocalSrc(src);
         }
-        // Poll briefly for the blob to be populated by the CMS proxy
+        // Poll briefly for the blob to be populated by the CMS proxy.
+        // Cap attempts so the interval doesn't leak if the value never
+        // changes (e.g., src was already resolved or stays unresolved).
+        let attempts = 0;
+        const MAX_POLL_ATTEMPTS = 20;
         const interval = setInterval(() => {
+            attempts++;
             const resolved = getAsset(value, field).toString();
             if (resolved && resolved !== src) {
                 setLocalSrc(resolved);
                 clearInterval(interval);
+            } else if (attempts >= MAX_POLL_ATTEMPTS) {
+                clearInterval(interval);
             }
         }, 500);
         return () => clearInterval(interval);

src/templates/disease-catalog.tsx

@@ -112,7 +112,9 @@ interface QueryResult {
 const DiseaseCatalog = ({ data }: QueryResult) => {
     const { markdownRemark: post } = data;
     const imageFile = post.frontmatter.header?.background;
-    const backgroundImageUrl = getImageSrcFromFileNode(imageFile!);
+    const backgroundImageUrl = imageFile
+        ? getImageSrcFromFileNode(imageFile)
+        : undefined;
     return (
         <Layout
             header={