A WRAP_ETH that sets the input side and pays its WETH to anyone but the router now names that recipient on its Moved to line, or reads The sender for address(1). V4Router pays ETH from the router's own ETH, whoever a SETTLE names as payer. ETH the router already holds now pays first for the ETH a V4 step would take from the user, and only the rest is moved from the sender. An UNWRAP_WETH into the router keeps a known WETH amount as the ETH the router then holds. Model: opus-5-5