New kitten, bird safety advice needed!!!

Hello!
I would appreciate it if someone could give me advice on how they keep their parrots safe from their cat! Sorry if this is too long~

I have a Sun Conure: Mochi, a ragdoll: Cody, and a newly rescued kitten: Nimbus.
Mochi and Cody got along completely fine. Cody has had no interest in him EVER, so I've never had to take precautionary steps with the two before. Inversely, Nimbus has been VERY interested in Mochi. I rescued Nimbus a week ago, he was about to be put down in a shelter I was visiting and I just couldn't let that happen...
Mochi's cage is at a really good location since it's in the center of the house. He's never alone, and he gets sunlight from sunrise to sunset. The bad thing about Mochi's cage is that Nimbus can fit his paws/claws through the cage. I want to be able to leave the house without putting Nimbus in the basement or laundry room, and I'd prefer to keep Mochi's cage at its current location.
Nimbus doesn't seem to be out for the kill, only VERY curious. What I've currently been doing is when he shows interest to say "no", if he continues I say no again and then spray him with water. He seems to be understanding that it's not acceptable behavior in front of me, but I think that can only go so far...

Do people have any training tips that could keep Mochi from being a toy when I'm away? Is that even possible to accomplish ? Or would anyone know any barricades that can keep a cat out?

Mochi's cage looks like this:



Thanks for your time

Just my 2 cents worth. It won't be if one of your cats gets your bird, but when. In my opinion, there is no safe way to have cats and birds in the same room unsupervised, let alone supervised. I have three cats which are closed away in the main part of the house. We have a kitchen that separates the main part of the home from the bird room and I still take precautions to ensure all doors are closed at all times. I would hate to have you find out the hard way that it wasn't safe to let them in the same room unattended. JMO. And thanks for rescuing the cat...that's our story as well.. hard to close your eyes to an animal in need.