A C# caller that leaves ChunkHash, MessageId or RecordKey null writes msgpack nil; the
reference reads it back as null, treats it as blank and answers found:false. Rust now
decodes nil as blank in content chunk requests, so those requests are answered with the
reference bytes instead of dropped. Three nil vectors from the reference server are
judged by decoding them in Rust. Record two content-plane limits in the parity scope.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
5b538aaf07