HmacSHA256 signer returning sha256=<lowercase-hex>. 5 unit tests covering known vector, prefix, hex casing, and different secrets/bodies. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
HmacSHA256 signer returning sha256=<lowercase-hex>. 5 unit tests covering known vector, prefix, hex casing, and different secrets/bodies. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>