Implement self-describing chunked protocol ([201][UINT16][data], [202] end) for AsyncSegment mode, enabling true zero-copy, pipeline-parallel serialization/deserialization of large arguments in SignalR.
- AsyncPipeWriterOutput now reserves a 3-byte header per chunk and supports two backpressure modes.
- AcBinaryHubProtocol routes streamable arguments through WriteMessageChunked, with chunk accumulation and background deserialization on the receiver.
- Logging now uses ILogger; documentation and wire format details updated.
- Consumer code updated to use new mode and diagnostics.
- Improves throughput, memory usage, and maintainability for large payloads.