Remove SegmentBufferReader; unify on AsyncPipeReaderInput
Migrates all SignalR chunked streaming receive logic to AsyncPipeReaderInput, fully removing SegmentBufferReader and SegmentBufferReaderInput from the codebase. Updates all references, deserialization paths, and documentation to reflect the new unified primitive. Marks ADR-0003 as accepted (partially executed), closes related TODOs, and clarifies protocol docs. Sets DoubleBuffered as the default FlushPolicy. No wire format or behavioral changes; all tests pass.
Refactor SignalR protocol registration; add DI options
- Added AcSignalRServerProtocolExtensions and AcSignalRProtocolExtensions for idiomatic AddAcBinaryProtocol registration (server/client), using a shared BuildProtocol factory for DI/IOptions/inline config.
- Introduced AcHubConnectionOptions and AcSignalRConnectionExtensions for configuration-driven client setup.
- Refactored AcSignalRClientBase to require a preconfigured IHubConnectionBuilder, moving all connection/protocol config out of the base class.
- Removed legacy protocol constructors; all protocol instantiation is now options-based.
- Enforced WASM + AsyncSegment guard in AcBinaryHubProtocolOptions.Validate.
- Updated SIGNALR_BINARY_PROTOCOL.md and GLOSSARY.md for new DI/config patterns.
- Minor: updated settings.local.json with new DLL/plugin inspection commands.
Loretta