Fix widget not rendering when initial HTML has unclosed tags

Load the iframe shell empty and stream all content via postMessage
after the iframe loads. Previously, partial streaming fragments
(e.g. an unclosed <style> tag) inserted into the shell would consume
the bridge script, preventing all subsequent postMessage updates.

Author: GeneralJerel

apps/app/src/components/generative-ui/widget-renderer.tsx

@@ -497,19 +497,21 @@ export function WidgetRenderer({ title, description, html }: WidgetRendererProps
   }
 
   // Initialize the iframe shell once when html first appears.
-  // After that, stream content updates via postMessage — no iframe reload.
+  // Shell loads EMPTY so partial streaming fragments (e.g. unclosed <style>)
+  // can't break the bridge script. All content is streamed via postMessage.
   useEffect(() => {
     if (!html || !iframeRef.current) return;
 
     if (!shellReadyRef.current) {
-      // First time: load the full document so the shell (styles, bridge JS) is ready
       shellReadyRef.current = true;
-      committedHtmlRef.current = html;
-      iframeRef.current.srcdoc = assembleShell(html);
+      iframeRef.current.srcdoc = assembleShell();
       return;
     }
 
-    // Subsequent updates: stream content into existing iframe via postMessage
+    // Wait for iframe to load before sending postMessage
+    if (!loaded) return;
+
+    // Stream content into existing iframe via postMessage
     if (html === committedHtmlRef.current) return;
     committedHtmlRef.current = html;
 
@@ -520,7 +522,7 @@ export function WidgetRenderer({ title, description, html }: WidgetRendererProps
         "*"
       );
     }
-  }, [html]);
+  }, [html, loaded]);
 
   // Detect when html has stopped changing (streaming complete).
   // Resets a debounce timer on every html update — settles after 800ms of no changes.