Fixed the issue where variables were not displayed in the switch operator #3221 (#8601)

### What problem does this PR solve?

Feat: Fixed the issue where variables were not displayed in the switch
operator #3221

### Type of change


- [x] New Feature (non-breaking change which adds functionality)

web/src/pages/agent/form/switch-form/use-watch-change.ts

@@ -9,8 +9,9 @@ export function useWatchFormChange(id?: string, form?: UseFormReturn) {
 
   useEffect(() => {
     // Manually triggered form updates are synchronized to the canvas
-    if (id && form?.formState.isDirty) {
-      values = form?.getValues();
+    console.log('🚀 ~ useWatchFormChange ~ values:', form?.formState.isDirty);
+    if (id) {
+      values = form?.getValues() || {};
       let nextValues: any = {
         ...values,
         conditions: