I’ve cut and pasted vector art from Illustrator to PhotoShop and chose “smart object” when I pasted it.
Is there a way to convert the smart object to a shape layer now so I can edit the very simple art directly in PhotoShop?
You cannot convert a Smart Object to a Shape Layer.
The best option is to double-click the Smart Object, which should open it up in Illustrator, then copy it. Jump back to Photoshop and paste it, choosing
Shape Layer when the options pop up. Then delete the Smart Object if desired.