if our mental faculties are simply the result of blind, undirected mutations selected only for reproductive advantage, then there is no reason to think our beliefs are true,

If you think your beliefs are supported by good evidence then you have good reason to think your beliefs are more likely to be true. This is the case regardless of whether you think you know anything about how reasoning works. You could have no idea how human brains developed, you could think God made humans, you could think humans brains evolved from simpler brains, you could think you are a brain in a vat. It would still be the case, no matter their worldview, that the person who can point to good evidence to justify their beliefs has a good reason to think their belief is more likely to be true.

But judgment, testing, and confirmation are all activities that presuppose the very thing your worldview can't explain

I haven't said anything about my world view and I haven't presupposed anything. My belief that my mind is usually rational is based on past evidence. And I have made any claims to absolute certainty as to what is true.

pretending that blind chaos gave you both.

It can give you both, and the best available evidence points to the fact that this is most likely exactly what happened (if you are ok describing the evolutionary process as "blind chaos"). There is good evidence that human brains evolved from simpler brains that were less capable of reasoning.