Plant it at least 10 feet from the deck. Root damage from trees is overstated.

I just take a look at the deck and there's no way I could plant it 10 feet from the edge of the deck. It was about 5 feet from the deck to a public fenced area.

I know at least two cases of people building their decks around already existing cherry trees, without any rooting damage to the deck. The trees probably took some root damage though. Largest problem was birds sitting in the trees, eating the cherries and pooping on the deck.

The deck sits right on the ground, with no air space beneath?

Right. It is just one level.

How much sunlight does a cherry tree need?