Rust crypto core: FrodoKEM port, hybrid suite, Fury, STREAM, key files

FrodoKEM-640-SHAKE is ported from CIRCL v1.6.4 (the RustCrypto crate
implements the incompatible ISO variant) and reproduces the reference
NIST KAT digest. ML-KEM-768 comes from RustCrypto ml-kem. Derivation,
encapsulation, implicit rejection, KEK, header MAC, header parsing,
STREAM and Argon2id key files all match vectors from the Go oracle, Go's
files decrypt in Rust, and Go decrypts Rust's.

Co-Authored-By: Claude <noreply@anthropic.com>

src/crypto/mod.rs

@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+//! Fury file encryption, compatible with the Go `internal/pqcrypt`,
+//! `internal/format` and `internal/stream` packages.
+
+pub mod frodo;
+pub mod fury;
+pub mod header;
+pub mod kem;
+pub mod stream;