Not to be a downer, but I suspect that we are decades away from meaningful diagnostics that would get you anywhere close to being able to declare someone in "perfect health". In fact, I will say that we are 20 years away, and we always will be.[1] For someone who believes that "perfect health" is of little meaning in an adaptive evolutionary framework, this isn't a big issue, but it could be disquieting to some.

Let's say you sequence everyone's genome and can do it for $0 per person. Even if you could, having a genome sequence gets you only so far. We don't know what many genes do; even less so do we know what changes in their structure or in their regulatory elements may do. We have useful, powerful ideas coming from evolutionary biology, but these won't be enough to let one feel confident about health claims.

And this says nothing about infectious, environmental, and behavioral components to risk.

[1] = I know that the fusion "20 years away and always will be" actually refers to the fact that if insufficiently funded it will always be 20 years away. But most people don't know that part of the reference, so I will ignore it at will.