fix: context menu not opening when right-clicking different Vue nodes (#7644)

## Summary
- Fixed issue where right-clicking on one Vue node then another would
close the context menu instead of repositioning it
- Added `showNodeOptions` function that always shows the menu at the new
position (used for contextmenu events)
- Kept `toggleNodeOptions` for the "More Options" button where toggle
behavior is expected

## Test plan
- [ ] Right-click on a Vue node to open context menu
- [ ] Right-click on a different Vue node - menu should immediately show
for the new node
- [ ] Click "More Options" button when menu is open - should close the
menu
- [ ] Click "More Options" button when menu is closed - should open the
menu



https://github.com/user-attachments/assets/bb31c2e4-12b4-4786-96ac-23b1e2b4daa0



┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7644-fix-context-menu-not-opening-when-right-clicking-different-Vue-nodes-2ce6d73d36508145bc30fe6947b6808a)
by [Unito](https://www.unito.io)

src/components/graph/NodeContextMenu.vue

@@ -263,7 +263,7 @@ function onMenuHide() {
 }
 
 onMounted(() => {
-  registerNodeOptionsInstance({ toggle, hide, isOpen })
+  registerNodeOptionsInstance({ toggle, show, hide, isOpen })
 })
 
 onUnmounted(() => {