Simulate one unsigned Base transaction before an agent signs it. Runs eth_call and gas estimation on current chain state, decodes the intent (ERC-20 transfer, approve, NFT setApprovalForAll), flags unlimited approvals, calldata sent to a non-contract, zero-address targets, reverts and destination risk labels such as phishing or sanctions. Returns ALLOW, WARN, BLOCK or INCOMPLETE with findings. No key or signed transaction is requested.