fix app.js no graph defined (#3754)

* local test

* fix "graph" not found

* fix

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Co-authored-by: Xiujuan Li <xiujuali@amazon.com>

web/scripts/app.js

@@ -2239,7 +2239,7 @@ export class ComfyApp {
 			const node = LiteGraph.createNode(data.class_type);
 			node.id = isNaN(+id) ? id : +id;
 			node.title = data._meta?.title ?? node.title
-			graph.add(node);
+			app.graph.add(node);
 		}
 
 		for (const id of ids) {