Add Subscription Days Remaining Counter

Please add a countdown showing the number of days remaining on the user's subscription.

The app currently shows the subscription expiration date, but adding a clear "X days remaining" counter would make it much easier to know how much time is left at a glance.

Please keep the existing expiration date and display the remaining days alongside it rather than replacing the date.

It would also be helpful to place this information somewhere noticeable, such as on the main page, so users can easily keep track of their subscription status.