Have your contractor look into Flexinstall LED lights. They can be installed with or without junction boxes, so if there's enough room to run electric, in theory, you can have ceiling lights.

https://www.homedepot.com/p/Flexinstall-LED-14-in-White-Disklight-Recessed-Ceiling-Light-for-Home-with-5CCT-DuoBright-Dimming-92060/324109301

As for a fan, I'd see if you can do a wall mounted exhaust fan, since you have a window in the space I assume you can access the exterior, which would have been the path through the ceiling too.

There are so many directions you can go in terms of style, do you have any general inspiration that you've been thinking of for the space that you can share?

A couple things I'd prioritize if it were my space and I couldn't do ceiling lighting

1. opaque globes/shades to minimize the intensity of bulbs that are closer to eye-level than if they were ceiling mounted.

2. closed globes (rather than open access to bulbs) making them easy to clean and protected from moisture.

A few concepts here

If you can have drywall for your ceiling, you can have LED lights. Like the above lights, the Dals ones I used in my shower ARE their own junction box, can be installed in the depth of the drywall ceiling, and just need to have wire running to them. They come damp rated or not.

https://dals.com/product-category/recessed/slim-panels/

As for ventilation, it is on an outside wall. Wall fans used to be a thing. If you can have a window, why can’t you have a through-wall exhaust fan?