As a user, I should see a full-screen view of my countdown moments before it expires with the option to exit it early.
This full-screen view must pop up one minute before and display the number of seconds until expiry in real time.
When the countdown expires, it should display a congratulatory message and allow the user to exit the view with a prominent button. Upon exit, the app redirects to the countdown's details page.
The preference for the countdown alarm view to be shown should be on by default and must be configurable when a countdown is created and edited.
As a user, I should see a full-screen view of my countdown moments before it expires with the option to exit it early.