test(frontend): extend coverage for comfyui widgets and helpers

scripts/app.js

@@ -0,0 +1,12 @@
+export const app = {
+  canvas: { ds: { scale: 1 } },
+  extensionManager: {
+    toast: {
+      add: () => {},
+    },
+  },
+  registerExtension: () => {},
+  graphToPrompt: async () => ({ workflow: { nodes: new Map() } }),
+};
+
+export default app;