Access to stderr stream in StdioClientTransport

[sefinx]

Hi,

I'm using StdioClientTransport from @modelcontextprotocol/sdk/client/stdio.js to launch and communicate with an MCP server from my app. I'm passing stderr: 'pipe' in the constructor options, but I can't find a way to access the underlying stderr stream to read error messages from the server.

It would be very helpful if StdioClientTransport exposed the underlying ChildProcess instance (or at least the stderr stream) so I can log or handle the server’s stderr output in my app.

Would you consider exposing the child process or adding a hook to access stderr?

Thanks!