Checks one address on Ethereum, Base, Arbitrum, Optimism, Polygon or BNB Smart Chain against the open verification registry and against the chain itself. For a proxy the answer is deliberately split in two: whether the proxy is verified says almost nothing, whether the implementation it currently points to is verified is the real question, and both are reported separately with the implementation address read from the EIP-1967 storage slot, the EIP-1167 clone pattern or an implementation() call —