Check a Base address before an agent pays or approves it. Input: one address. Output: allow or warn. Reports wallet or contract, whether the wallet has sent a transaction, whether a contract already had code 7 days ago, and whether it is a proxy (EIP-1967, EIP-1167, or implementation()). Warns on contract_is_new, proxy, or no_outgoing_transactions. Wallet age is unknown. A deleted contract looks like a wallet. Not proof of theft.