fix: a swap deadline later than a date can hold is stated in words (closes #437)

decode() rendered the Deadline line with toISOString(), which throws on a
date past 275760-09-13, the last a JavaScript date can hold. A later
deadline, such as the uint256 maximum, therefore left the whole swap
undecoded, with nothing saying why. That line now reads
"After 275760-09-13 00:00:00 (no deadline in practice)".

Model: opus-5-5

TODO.md

@@ -45,6 +45,12 @@ but the review is broader than any of them.
 
 # Completed Steps
 
+- 2026-10-04: A swap whose deadline is later than a JavaScript date can hold is
+  decoded ([#437](https://git.eeqj.de/sneak/AutistMask/issues/437)). A date
+  reaches only to 275760-09-13, so a later deadline, such as the `uint256`
+  maximum, made the `Deadline` line throw, and the approval screen showed the
+  swap as an undecoded contract call with nothing saying why. That line now
+  reads `After 275760-09-13 00:00:00 (no deadline in practice)`.
 - 2026-10-04: The swap decoder reads two router zeros the way the router does
   ([#415](https://git.eeqj.de/sneak/AutistMask/issues/415)). A V2 exact-in
   `amountIn` of zero means an earlier step already sent the tokens to the pair;