Ideas for cat proofing crib?

I know canopies are not the option.

I have been trying to brainstorm a way so that we can keep baby safe (#1 priority) but also not lock our cats out of our bedroom. our cats have always slept in our room, they play there, they hang our there during the day - its definite their safe space - and with all the changes they'll experience with a new baby i'm hoping there is some sort of alternative to taking that room from them. If there's no other option so be it, cats are out - but wanted to see if anyone has figured out this issue before throwing in the towel.

ideas I've had, but can't get to work:

• large screen tent in bedroom, put crib in that
  • idea: we could unzip, walk in, place baby in crib, zip back up. Cats can't get in, baby cant pull tent down onto themselves
  • issue: "air pooling" - Co2 doesn't escape as well due to non-breathable fabric roof used to keep out the rain, baby rebreathing Co2 (which is crazy, i'd never considered this with mesh)
• Magnetic Wall Screen
  • idea: create a ceiling-to-floor box with magnetic screendoors around the crib - a room-within-a-room that the cats can't get into
  • issue: sturdyness. There also doesnt seem to be "screen walls", only doors - would need to be a 3-sided box (4th side being the real wall). Basically product doesnt seem to exist (though my research says if it did, the size and open top wouldnt create Co2 hazard)
• Pet-gate
  • idea: same as wall screen, but without the mesh. boxed in on 3 sides. would look like the jail gotham uses for the joker in dark knight, but aesthetics arent our concern. no Co2 concern
  • issue: gates only seem to be for doorways, this would be coming off a flat wall - need the 3 sides. Don't think this product exists.

have also looked at play-yards since they create a boxed in area on the floor, but nothing is tall enough to keep the cats out. There is also the DIY projects, but dont think it's worth buying materials, building, hoping its safe and hoping it works - at that point the cats are just going to have to deal.

Thanks!!