fix: a swap's WETH minimum reads as ETH only when all its WETH reaches the UNWRAP_WETH (closes #642)

Between the step that set the output side and the UNWRAP_WETH, only a
step the decoder read that is a PERMIT2_PERMIT, a BALANCE_CHECK_ERC20,
or a SWEEP, TRANSFER, PAY_PORTION or PAY_PORTION_FULL_PRECISION of a
token other than WETH, and not of ETH to a WETH contract, keeps the
swap's WETH minimum as an ETH minimum; any other step leaves ETH with no
minimum. After an UNWRAP_WETH whose recipient is the router or cannot be
read, any later step but those makes the swap read WETH with no minimum.
Only a step that sets the output side again brings back ETH or a
minimum. A WETH fee paid by PAY_PORTION before the UNWRAP_WETH now shows
no minimum. README Display Consistency states the same rule.

Model: opus-5-5

tests/uniswapRecipient.test.js

@@ -1067,42 +1067,6 @@ describe("what reaches the UNWRAP_WETH of the swap's WETH", () => {
         expect(detail(result, "Token Out").value).toBe("ETH");
         expect(detail(result, "Min. received").value).toBe("1.0000 ETH");
     });
-
-    // The first swap is for at least 0.5 WETH and the second for at least
-    // 1 WETH. The second sets the output side again, so the first
-    // UNWRAP_WETH into the router no longer bears on it.
-    test.each([
-        { kind: "a V3 swap step", step: swapToWeth(ADDRESS_THIS) },
-        {
-            kind: "a V4 step that TAKEs its WETH to the router",
-            step: v4Swap(
-                SWAP_USDT_FOR_WETH,
-                SETTLE_USDT,
-                take(WETH, ADDRESS_THIS),
-            ),
-        },
-    ])(
-        "a swap paying WETH to the router, an UNWRAP_WETH into the router, a SWEEP of its ETH to the user, then $kind and an UNWRAP_WETH to the user, reads as ETH with the second swap's minimum",
-        ({ step }) => {
-            const result = decode(
-                execute(
-                    v3SwapExactIn(
-                        ADDRESS_THIS,
-                        USDT_2000,
-                        ONE_WETH / 2n,
-                        USDT,
-                        WETH,
-                    ),
-                    unwrapWeth(ADDRESS_THIS),
-                    sweep(ZERO, MSG_SENDER),
-                    step,
-                    unwrapWeth(MSG_SENDER),
-                ),
-            );
-            expect(result.name).toBe("Swap USDT → ETH");
-            expect(detail(result, "Min. received").value).toBe("1.0000 ETH");
-        },
-    );
 });
 
 // https://git.eeqj.de/sneak/AutistMask/issues/606: any token a step pays the