List extendable delegate candidates for a `receiver` and `resourceType` (ENERGY|BANDWIDTH). Optional `suggestData` scores an extend-and-buy scenario for planning purposes. Read-only; does NOT create orders or change on-chain state. Works without `mcp-session-id`; when a session is present, auth is forwarded so results can reflect the logged-in account where supported. NOTE: this is GraphQL market data for discovery only. To actually submit an extension, call the authenticated REST `POST /v2/get-extendable-delegates` with `extendData` (payload shape differs from this GraphQL response).
ConnectorNo auth