post
https://api.testnet.rise.trade/v1/auth/register-signer
Register a signer key for an account. Requires two EIP-712 signatures:
1. Account signs RegisterSigner:
RegisterSigner(address signer, string message, uint40 expiration, uint256 nonce)Struct hash: keccak256(abi.encode(TYPEHASH, signer, keccak256(bytes(message)), expiration, nonce))
2. Signer signs VerifySigner:
VerifySigner(address account, uint256 nonce)Struct hash: keccak256(abi.encode(TYPEHASH, account, nonce))
Both use the same EIP-712 domain from GET /v1/auth/eip712-domain.