A bit late to the party but i realised this that since you mentioned Google, technically the whole internet is pretty much like a vault with hyperlinks being the uni-directional links.
Especially given the fact that a hug number of crawlers have already archived these webpages links and hyperlinks makes it even more of a better place to start .
Another point i wanted to make was that rather than having a direct connection from one note to another would it make sense to go from Note A to Note B via a Lable note which contains the reason for linking A to B.
Not only do we quantify the connection between the note but we also elaborate on why the connection exists in the first place making the links more rich in nature. This probably would mimic graphql ig