Is there a viable career path for researchers who choose to focus on replication instead of novel discoveries? I assume replications are perceived as less prestigious, but it's also important work.

The closest thing we have is, in security / privacy / cryptography, you can write "attack" papers.

It's not perfect. You don't get any credit unless you can demonstrate a substantial break of the prior work. But it's better than in a lot of other fields.

sadly no, this is not a thing and it's critically needed.

top on my list of things to do if i were a billionaire: launch an institute for the sole purpose of reproducing other's findings.