Module cache 

Bounded LRU caches used by the remoting hot paths.

RemoteActorRefProvider keeps an LRU of ActorPath ↔ RemoteRef and SerializerRegistry keeps an LRU of serializer-id ↔ manifest. Both speed up repeat lookups on the inbound dispatcher.

We hand-roll a small LRU instead of pulling in lru so the crate stays dep-free.

Structs

LruCache

Bounded LRU cache. Eviction is O(N) per insert in the worst case (we scan the access order), but N is the cache capacity — small in practice (≤4096 for the remoting use case).