EIP-7702: Set EOA Code

// SetCodeTx transaction structure (EIP-7702 Type 4 transaction)
// This transaction type enables EOAs to temporarily delegate code execution
type SetCodeTx struct {
    // Standard transaction fields
    ChainID   *uint256.Int                // Chain ID for EIP-155 replay protection
    Nonce     uint64                      // Account nonce (must be sequential)
    GasTipCap *uint256.Int                // Priority fee per gas (EIP-1559)
    GasFeeCap *uint256.Int                // Maximum fee per gas (EIP-1559)
    Gas       uint64                      // Gas limit for transaction execution
    To        *common.Address             // Recipient address (can be self for delegation)
    Value     *uint256.Int                // ETH value to transfer
    Data      []byte                      // Contract call data to execute with delegated code
    AccessList ethtypes.AccessList        // EIP-2930 access list for gas optimization

    // EIP-7702 specific fields
    AuthList   []SetCodeAuthorization     // List of code delegation authorizations

    // Transaction signature (signs entire transaction)
    V *uint256.Int
    R *uint256.Int
    S *uint256.Int
}

// SetCodeAuthorization enables an EOA to authorize code delegation
// Each authorization is separately signed and validated
type SetCodeAuthorization struct {
    // Delegation parameters
    ChainID uint256.Int     // Target chain ID (0 = valid on any chain)
    Address common.Address  // Contract address to delegate code from
    Nonce   uint64         // Authority's current nonce (prevents replay)

    // Authorization signature (separate from transaction signature)
    // Signs: keccak256(0x05 || rlp(chainId, contractAddress, nonce))
    V uint8           // Recovery ID
    R *uint256.Int    // Signature R value
    S *uint256.Int    // Signature S value
}

// Delegation Bytecode Format (automatically generated)
// When delegation is active, the EOA's code becomes:
// 0xEF0100 + contractAddress (23 bytes total)
// - 0xEF01: Delegation marker (EIP-3541 compliance)
// - 0x00: Delegation version
// - contractAddress: 20 bytes of target contract