pub fn cascade_conflicts_with_paging(
kv_peer_set: bool,
flag_raw: Option<&str>,
) -> Result<bool>Expand description
2026-09-25: true when kv_peer_set and flag_raw selects the paging backend;
an invalid flag_raw is an error. CascadeBackend evicts through per-head
write_from_host, which KvPagingBackend refuses.