//! Storage layer — shared dictionary, hexastore, bulk loader.
//!
//! Submodules:
//! * [`dict`] — dictionary CRUD + shmem-aware `put_term_full`.
//! * [`hexastore`] — partitioned `_pgrdf_quads` CRUD + `add_graph`.
//! * [`loader`] — Turtle ingest with per-call cache + batched
//! prepared INSERTs (LLD §4.3 phase A).
//! * [`shmem_cache`] — cross-backend dict cache in Postgres shmem
//! (LLD §4.1).
//! * [`stats`] — `pgrdf.stats()` + `pgrdf.shmem_reset()` UDFs.
//!
//! Reference: SPEC.pgRDF.LLD.v0.2 §3, §4.1, §4.3 and
//! `docs/02-storage.md`.