No, planets cannot be cloaked. The idea you posted will result in an error as far as I know. The cloak level ability is for ships, not stellar objects. You can
hide a planet but it will not be cloakable/uncloakable with a command. Give it the 'sight obscuration' ability, which
is a stellar ability, and everything in the sector, including the planet itself, will be invisible until you have sufficient sensors.
We'd like to see planetary cloaks but it's one of a zillion things we'd 'like' to see.
