//! Persistence backends.
//!
//! Single node runs on [redb](https://github.com/cberner/redb) — pure Rust, two
//! crates deep, with a stable on-disk format. The active-active topology
//! (run-ownership leases plus fencing epochs, arbitrated by the store) is
//! designed for `PostgreSQL`. The
//! [`JournalStore`](crate::journal::JournalStore) contract is identical for
//! both, and the invariants it demands — fencing, exactly-once, chaining — are
//! expressed as constraints so a backend cannot quietly omit one.
pub use PostgresStore;
pub use RedbStore;