Orders and vault operations

struct Order {
    uint256 salt;
    address maker;
    address signer;
    address taker;
    uint256 tokenId;
    uint256 makerAmount;
    uint256 takerAmount;
    uint256 expiration;
    uint256 feeRateBps;
    uint8   side;             // 0=BUY, 1=SELL
    uint8   signatureType;    // always 1 (VAULT); 0 (EOA) is rejected
}

// marketExchange / marketGeneration: see Detect a market's generation
const exchange = marketExchange(market);
const maker    = vaults.find(v => v.generation === marketGeneration(market))!.vaultAddress;
const domain   = { name: 'PredictStreet', version: '1', chainId: contracts.chainId, verifyingContract: exchange };

const order = {
  salt, maker, signer: eoa.address,
  taker: '0x0000000000000000000000000000000000000000',
  tokenId: BigInt(tokenId),
  makerAmount, takerAmount, expiration: 0n,
  feeRateBps: BigInt(market.feeTakerBps),
  side: 0, signatureType: 1,
};
const signature = await eoa.signTypedData(domain, types, order);   // `types`: the Order type from EIP-712 signing
// POST /api/orders/place with `maker` = the same vault, as on Placing orders

const userSig = await eoa.signTypedData(
  { name: 'PredictStreetVault', version: '1', chainId: contracts.chainId, verifyingContract: vault },
  WITHDRAW_ERC20_TYPES,   // the WithdrawERC20 type from WithdrawERC20 EIP-712
  { token: contracts.usdc, to, amount: parseUnits(amount, 6), salt, deadline },
);
await fetch(`${BASE}/api/withdrawals/request`, {
  method: 'POST', headers: auth,
  body: JSON.stringify({ amount, destination: to, salt: salt.toString(), expiry: Number(deadline), userSig, vault, totpCode }),
});

const sig = await eoa.signTypedData(
  { name: 'PredictStreetRedeem', version: '1', chainId: contracts.chainId },   // no verifyingContract
  { RedeemAuthorization: [
      { name: 'owner', type: 'address' }, { name: 'marketId', type: 'string' },
      { name: 'outcomeIndex', type: 'uint8' }, { name: 'deadline', type: 'uint256' } ] },
  { owner: eoa.address, marketId, outcomeIndex, deadline },
);
const { v, r, s } = Signature.from(sig);
const body = { marketId, outcomeIndex, vault, auth: { deadline, v, r, s } };