Adds fetched_at to RemoteActor, configurable TTL via builder (.actor_cache_ttl_secs, default 24h), and get_or_refresh_remote_actor helper that re-fetches stale actors from origin. Closes #3
Adds fetched_at to RemoteActor, configurable TTL via builder (.actor_cache_ttl_secs, default 24h), and get_or_refresh_remote_actor helper that re-fetches stale actors from origin. Closes #3