Store selected country in localStorage for persistence across page reloads

Currently, when a user refreshes the page, their country selection is lost unless it was specified in the URL parameters. users need to reselect their country after each page reload.

No file, test, or entry point is named in the issue. Locate the code that handles country selection and URL parameters, then inspect how the selected value is restored on page load; the work is done when a refreshed page retains the user's country selection without requiring URL parameters.

Written by the indexing model from the issue text.