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`hermes mcp login <server> --flow device` took `authorization_servers[0]` from the protected-resource metadata and failed when that entry was a browser-only or issuer-inconsistent server, even though a later entry was the issuer-bound device_code server meant for headless clients (Higgsfield advertises exactly this shape: a PKCE server first, the device server second). Discovery now tries each advertised server in order and binds to the first whose metadata issuer matches its advertised URL and that offers device authorization. Issuer validation (RFC 8414 / SEP-2468) is unchanged per server; a single-server resource raises exactly the error it raised before, and a multi-server resource with no usable entry reports every attempt. The browser path (`tools/mcp_oauth_manager.py` pre-flight) is deliberately left on the SDK's own first-entry selection: the SDK's 401-branch discovery re-selects `authorization_servers[0]` itself, so a divergent pre-flight pick would only desynchronise the cached metadata from what the SDK authorizes against.