v0.31.0

Added

• Public reflection client, matching vgi-rpc 0.50.0:
  vgi_rpc_client::list_protocols(&mut target) -> Vec<HostedProtocol> and
  describe_protocol(&mut target, name) -> ServiceDescription, also as
  RpcClient / HttpClient methods. target is any client the crate hands
  out (subprocess, pipe, shm, unix, TCP, TLS, raw Iroh, HTTP, HTTP over Iroh),
  bound to any protocol; its own connection is reused and never closed
  (ReflectionTarget is sealed, the per-transport hook private).
• HostedProtocol { name, version, hash, deprecated, deprecation_message, features }, in server order.
• ReflectionError::{NotSupported, Rpc} and ReflectionNotSupportedError
  (derefs to the server's RpcError): protocol_not_supported,
  method_not_implemented or UNIMPLEMENTED answers to list_protocols, and
  an HTTP bare 404, are "no reflection" -- never an inferred listing; the
  connection stays usable. describe_protocol lists first, so an unknown
  name is Rpc with error_kind = "protocol_not_supported".

Changed

• RpcClient::list_protocols / HttpClient::list_protocols return
  Result<Vec<HostedProtocol>, ReflectionError> (was ProtocolList of
  ProtocolSummary, both now crate-private); describe_protocol lists first,
  fills server_id / request_version, and returns ReflectionError.
  reflection_payload, parse_protocol_list and parse_service_description
  are no longer public.
• HttpClient: a failure status whose body is not Arrow is now
  HttpError "HTTP {status}: response is not a valid Arrow IPC stream …", as
  in the reference client, rather than an IPC decode error that hid the status.