In my previous life at Facebook, I worked on the infra team and worked on a cluster manager similar to kubernetes, thats where I first heard the term sidecar. Something about the concept of a binary running alongside the pod powering other related things felt strong.
In most parts this is the inspiration for naming the AI brain: sidecar
Unfortunately, there are a distinctly limited number of words that can communicate a particular concept - the pigeon-hole principle suggests duplication will be inevitable.
Ambiguity's only really a problem when the same term is used multiple ways in similar contexts. I think it's very unlikely that anyone will get confused between these two usages.
https://support.apple.com/en-us/102597