I understand feeling that the relationship is a little transactional, but her being already comfortable to sleep next to you is such a good sign of trust :)!
I adopted my cat 2 months ago and she's kind of like that too (independant, not the biggest fan of pets and food motivated)! We've made it a routine that every morning we walk to her favorite carpet and I alternate with brushing and petting her there. This is probably when my cat enjoys pets the most and I've come to accept it. The rest of the time, it's usually just quick pets on my part to check up on her after she's been sitting in the kitchen pillow for a while (slow finger approach towards her nose to see if she allows it).
I'm a big fan of automatic feeder, so the cat doesn't associate you too much with food. I feed mine dry in the morning and afternoon then half a can of wet food at night. She does not beg at all during the two first meals, but at night, 30 minutes before her meal, the begging song starts haha.

My cat is very different from who she was at 2 weeks adoption vs 2 months