The baseline CLI<=> SDK protocol: all hook responses from this project go to stdout, and the CLI reads both stdout and stderr and combines them to interpret the hook response. This simplistic protocol has inherent limitations: cannot log diagnostic info!

Based on the arguments provided by the CLI to the SDK hook process, returns an appropriate Protocol interface for communicating with the CLI over the specified protocol.

Protocol implementation that only uses stdout, but uses message boundaries to differentiate between diagnostic information and hook responses.