V4Router pays a SETTLE of ETH from the router's own ETH, whichever payer
it names. The router holds the transaction's value. So a SETTLE of ETH
that names the router as payer now counts as paid by the user.
When an earlier step left ETH in the router, such a SETTLE gets lines of
its own. Its line reads "Up to" and its amount, and that amount never
joins the Amount total. When the decoder does not know the SETTLE's
amount, as for CONTRACT_BALANCE, its line reads "Unknown (could not be
decoded)", also on the step that sets the input side.
One existing row in tests/uniswapRecipient.test.js now expects the ETH
lines. Its SETTLE spends all the router's ETH, the transaction's value
included.
Model: opus-5-5
sneak