Holos is a very nice project, congratulations. Note that wrt Holos-Discover, the “How it works” does not explain the search mechanism, and the repo link gives a 404.
Regarding Holos-App the docs mention that it implements a “full ActivityPub server”, but it is unclear whether you mean “a full server” (S2S) or the “ActivityPub conformant Federated Server” specification profile, which in a quick peek is not what Holos-App is.. looks like? 