Here's an experiment that might be worth trying: temporarily delete a source file, ask your coding agent to regenerate it, and examine the diffs to see what it did differently.

This could be a good way to learn how robust your tests are, and also what accidental complexity could be removed by doing a rewrite. But I doubt that the results would be so good that you could ask a coding agent to regenerate the source code all the time, like we do for compilers and object code.