Launch an MCP server as a subprocess and build a client over its
stdin/stdout (stderr inherited for logging). command is the command line
(command[0] is the executable). The returned client is NOT yet
initialized — call initialize() (or ping() for a stateless probe).
close() runs the MCP stdio shutdown sequence on the subprocess.
Launch an MCP server as a subprocess and build a client over its stdin/stdout (stderr inherited for logging). command is the command line (command[0] is the executable). The returned client is NOT yet initialized — call initialize() (or ping() for a stateless probe). close() runs the MCP stdio shutdown sequence on the subprocess.