wechat-protocol 1.4.0

Native WeChat transport, authentication and protocol codecs
Documentation
The AES-GCM known-answer fixture in src/mmtls.rs is reproduced from
code/outer.py in Citizen Lab's wechat-security-report repository:
https://github.com/citizenlab/wechat-security-report

Copyright (c) 2025 Mona Wang
Used under the MIT License; see fixtures/LICENSE-CITIZENLAB.

The public MMTLS verification pins and business ECDH/signature pins are public
protocol constants from the Linux 4.1.13.26 default configuration. They are not
account credentials. Reference artifact SHA-256:
2749535f299ba67feb8ef80cab898bb0531fa8f376b16f8a72db706811c84132

Other test vectors contain synthetic inputs, RFC 5869 test-case 1 data, or
independently generated Python cryptography/zlib ciphertext. No private capture,
account identity, token, device state, message, or runtime executable is shipped.

The portable SILK SDK sources under vendor/silk are from kn007/silk-v3-decoder,
pinned commit 507be6bca8ce1fb977a061481f1d79e8c610e309:
https://github.com/kn007/silk-v3-decoder

The wrapper project is MIT licensed; the SILK SDK sources retain their Skype
BSD-style notices. Full license text and an allowlist of SHA-256 source hashes
are in vendor/silk/LICENSE-MIT, LICENSE-SDK and SOURCE.json. Only portable C and
headers are included. No codec binary from the official client is loaded.