Facilitator responses

{ success: true; payer: string } | { success: false; error: string }

{ success: true; txHash: string; network: string } | { success: false; error: string }

type SupportedResponse =
  | {
      success: true;
      chains: number[];
      tokens: {
        address: string;
        supportedMethods: ("eip3009" | "permit" | "permit2")[];
      }[];
    }
  | { success: false; error: string };