A BALANCE_CHECK_ERC20 of the sender with a zero minimum guarantees
nothing, and neither does one the router lets fail. Such a check set
Token Out and the minimum whenever the output side held no minimum.
After an UNWRAP_WETH that drops the minimum, a zero check of USDC
named USDC as Token Out. Such a check now sets neither line. A check
with a positive minimum is unchanged.
Model: opus-5-5
sneak