logic: Implement a live countdown timer for the Transaction Deadline

[AlAfiz]

Description

We previously added a "Transaction Deadline" setting, but users have no idea how much time is actually left once a trade is pending.
We need to add a live countdown timer that appears inside the swap confirmation modal once a transaction is submitted to the wallet.
Watching the seconds tick down adds a sense of urgency and transparency to the network confirmation process.
If the timer hits zero, the UI should automatically cancel the waiting state and show a timeout error.

Requirements

• Inside the isSubmitting state logic, capture the exact timestamp of when the button was clicked.
• Create a useEffect interval that ticks every 1 second, calculating the time remaining based on the user's deadline setting.
• Display the formatted time remaining (e.g., "04:59") inside the loading UI.
• If the timer reaches "00:00", clear the interval, stop the loading spinner, and display a "Transaction Expired" error toast.