Replace inaccurate GenerateKey docstring (it claimed to port Cryptographer.generateKeyString
directly but the input shape differs: server uses one hex digit per call, client uses
Random.Next(0,65535) per call). New doc is honest about the difference and explains why
it's safe. Add EncryptForNode_FixedVector_ProducesStableOutput: a pinned AES-CBC vector
that catches encoding/IV/padding regressions that would slip past the roundtrip test.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
