The committed value was the local dev address (localhost:8710, where
~/Projects/tgclient-mcp serves it) and the server ran with the wrong public
host, so the tools never connected. Both clones now use
https://tgclientmcp.gnexus.space/mcp.

No default headers: the key is per-user by design (BYOD settings field), and
until one is entered the server answers 401.