fix: decode Uniswap V2 exact-out swaps, input amount shown as a maximum (closes #283)

decode() had no arm for Universal Router command 0x09, so the approval
screen showed no token or amount for it. It now takes the path's first
token and amountInMax as the input side, the last token and amountOut as
the output side. With such a step, the Amount figure reads "Up to
<amount>" whichever step set it, on the approval, wait, success and error
screens, unless it reads "Unlimited", as an unbounded PERMIT2_PERMIT does,
or "All available (V4 open delta)". In every swap, UNWRAP_WETH makes
Token Out ETH only when the output side is WETH, on mainnet or Sepolia, or
no step set it; otherwise the output keeps its own token and figure.
decodeV2SwapExactOut() loses its eslint-disable comment.

Model: opus-5-5

TODO.md

@@ -45,6 +45,21 @@ but the review is broader than any of them.
 
 # Completed Steps
 
+- 2026-10-04: A Uniswap V2 exact-out swap (Universal Router command `0x09`) is
+  decoded on the approval screen
+  ([#283](https://git.eeqj.de/sneak/AutistMask/issues/283)). `decode()` in
+  `src/shared/uniswap.js` had no arm for it, so the screen named the step and
+  showed no token or amount. The input side is the path's first token with
+  `amountInMax`, the output side the last token with `amountOut`. When the
+  transaction has such a step, the `Amount` figure reads `Up to <amount>`,
+  whichever step set it, there and on the wait, success and error screens,
+  except where it reads `Unlimited` (an unbounded `PERMIT2_PERMIT`, or any
+  amount at or above the `uint160` maximum) or `All available (V4 open delta)`.
+  In every swap, `UNWRAP_WETH` makes `Token Out` ETH only when the output side
+  is WETH, on mainnet or Sepolia, or when no step set the output side; otherwise
+  `Token Out` and `Min. received` keep the output side's own token and figure.
+  V3 exact-out (`0x01`) is still not decoded.
+
 - 2026-10-04: The Send and confirmation screens no longer show an ETH balance, a
   token balance or a network fee below 0.000001 as zero
   ([#343](https://git.eeqj.de/sneak/AutistMask/issues/343)). The stored balances