My "aesthetic" sense is more about how modular the code is, how DRY (which is also an aesthetic balancing act), how clean the abstractions are and how well they fit the domain and the workflow.

Also, error handling.

Tests, specs, and docs are are all downstream of that.

So far I've found that AI does an adequate-to-very-good job up to a certain amount of code, then things tend to fall apart. The solution is modularity and clean interfaces - as it always was.

I'm not really sure. I'm mostly thrown into existing codebases and just modify things to fit the existing style, so I'm almost always evaluated purely by metrics. I do think your (TheOtherHobbes) standards are really good, though.