//! TLCP (GB/T 38636-2020) cryptographic toolkit.
//!
//! Building blocks for the Transport Layer Cryptography Protocol —
//! NOT a protocol implementation: no handshake state machine, no
//! record *framing* (no 5-byte header assembly), no I/O, no trust
//! decisions. The decomposition of the protocol onto these pieces lives
//! in `docs/tlcp-decomposition.md`.
//!
//! Shipped so far: [`key_schedule`] (GB/T 38636 §6.5) and [`record`]
//! (GB/T 38636 §6.3 record protection — the protect/deprotect
//! primitives for the four SM2-family suites; v1.7). The
//! no-confirmation SM2 key exchange TLCP's ECDHE suites use is NOT
//! here — it is standard SM2-KX generality and lives on
//! `sm2::key_exchange` behind the separate `sm2-key-exchange` feature
//! (a TLCP consumer enables both).