Get Server Config

An OAuth client Qualia was given, rather than one it registered itself.

RFC 7591 dynamic client registration is how a remote MCP server normally gets a client identity here: the SDK registers one at connect time and stores what comes back. Some authorization servers do not offer it at all — GitHub's remote MCP server, Slack's, and Microsoft Entra, which requires the customer to register their own app — and against those the handshake fails during registration, before a browser ever opens. Naming a client that is already registered is the way through (QUA-3219).