- useInfiniteStream: wrap fetchNextPage and refresh in useCallback so InfiniteScrollArea's IntersectionObserver does not re-subscribe on every parent render. - InfiniteScrollArea: do not render 'End of stream' until at least one item has loaded and the initial query has settled (was flashing on mount before first fetch). - AgentHealth: pass isLoading + hasItems to both InfiniteScrollArea wrappers.