Really like this framing. Separating facts from ephemeral context seems like a very strong design choice, especially because each layer should probably have different health rules and validation logic.

I have been thinking mostly about stale entries, duplicates, drift, and sync, but your point makes me think layer-aware memory health is important.

The hashing / integrity check idea is very interesting too, maybe overkill for some local workflows, but very relevant for higher-trust or enterprise settings.

And yes, it is open source, would definitely love to compare approaches.