Don’t think it’s the pads.
I got the bright idea to sharpie the whole surface of the rotor and see where it doesn’t contact, and there are lines like on the previous photos, but they are not continuous all the way around, which makes me think the rotor could be warped. Except I don’t have any symptoms of a warped rotor. I think I’ll just leave it as is until it starts giving me some kind of problems, then I’ll know what needs fixing.