fix bug

src/components/NodeCanvas.tsx

@@ -89,6 +89,9 @@ export function NodeCanvas({
 
   // Update NPC config when nodes change
   useEffect(() => {
+    // Skip if no nodes yet
+    if (nodes.length === 0) return;
+
     const newConfig = { ...npcConfig };
 
     nodes.forEach((node) => {
@@ -146,14 +149,16 @@ export function NodeCanvas({
       }
     });
 
+    // Update parent config
     onConfigChange(newConfig);
 
-    // Update output node preview
+    // Update output node preview with the new config
+    // Check if output node exists and if its preview data needs updating
     const outputNode = nodes.find(n => n.data.type === 'output');
-    if (outputNode) {
+    if (outputNode && JSON.stringify(outputNode.data.previewData) !== JSON.stringify(newConfig)) {
       setNodes((nds) =>
         nds.map((node) =>
-          node.id === outputNode.id
+          node.data.type === 'output'
             ? { ...node, data: { ...node.data, previewData: newConfig } }
             : node
         )