changes

A hot stream of CacheChanges for this cache. The default is an empty flow, so caches that cannot observe mutations are simply non-reactive; observable caches override this.

Delivery is latest-wins: under a burst that outruns a slow collector, the oldest change notifications may be dropped, but the most recent one is retained. Consumers that re-read on each event (e.g. Repository.stream) therefore always converge to the current value — they may skip intermediate values, never the latest.