I've built this for myself, but not across multiple machines. It scans the session logs of all coding harnesses I use, one extra thing it does is create embeddings to allow hybrid BM25/semantic search.
I think these kinds of tools are on of the few times I've spent time "using AI to work on my AI tools" that was actually a good use of time.
It's so useful to be able to say "search sessions for the time I was working on XYZ 3 months ago"
I've done exactly this.
I'm also experimenting with a 'dream mode' that extracts facts, and a 'librarian' that stores those facts in the MD wiki.
I don't know if there's a benefit to that yet, but I'm going to find out.