// SPDX-License-Identifier: Apache-2.0 // Copyright 2026 // //! `kei-ping` — cross-window agent heartbeat. Auto-selects backend. //! //! Constructor Pattern: 1 trait + 2 impl-cubes (sqlite / redis) + 1 dispatcher. //! Each cube ≤200 LOC, 1 responsibility. pub mod model; pub mod sqlite_store; pub mod redis_store; pub mod store; pub use model::{Heartbeat, PingFilter}; pub use store::{auto_select, BackendKind, PingStore};