## Bug description
Headless command menu items were interpreted as non headless command
menu items and opened in the side panel.
https://github.com/user-attachments/assets/44d8b4d3-9ee5-4f12-9ff8-b3ed51e5b3b6
## Fix
https://github.com/user-attachments/assets/9d6eb900-9817-4ceb-87aa-547ad046a5a1
- Command menu items received via SSE lack the nested `frontComponent`
relation (only `frontComponentId` is present), causing
`item.frontComponent?.isHeadless` to always be undefined.
- Add `frontComponents` to the metadata store's stale entity loading
- Rewrite `commandMenuItemsSelector` to join `commandMenuItems` with
`frontComponents` by `frontComponentId`