How To Link To Wiki At Spring Path?

I have a Spring Boot application running at thing.example.org. There are REST endpoints from that domain, such as thing.example.org/accounts and thing.example.org/regions, each with a structure below them.

What I want to do is have thing.example.org/wiki open a MediaWiki install, but I can't seem to get the redirect working. I'd prefer to not have to host the wiki at example.org/thing/wiki or wiki.thing.example.org.

I've tried setting Apache redirects, but that changes the URL. I've tried adding static resource links in Spring Boot, but that seems to want the wiki packaged in the JAR, which isn't doable.