I get the impression that there's a community of people within the ZK world that would be very much into that. For now, the local-only scene is cornered by Obsidian, which I use and adore.
Yeah, Obsidian got my attention too, but InfoSec from multiple companies gave it the thumbs down when we applied for purchase. At the last joint I asked 'em why, but they then very correctly reminded me they don't need to tell me why. Well, #@*$ you too, boys.
Anytype is local-first and plans to be self-hostable.
Dang, thanks for the lead. I saw they had undirected graphs in the feature list.