@Observable class ApplicationData {
   var userData: [Book] = [] 
   var viewPath = NavigationPath()
   var selectedBook: Book? = nil

   static let shared: ApplicationData = ApplicationData()
   private init() {
      userData = [
         Book(title: "Apple Intelligence for Masterminds", author: "J.D Gauchat", cover: "book1", year: 2026, selected: false),
         Book(title: "Steve Jobs", author: "Isaacson", cover: "book2", year: 2011, selected: false),
         Book(title: "Swift for Masterminds", author: "J.D Gauchat", cover: "book3", year: 2026, selected: false),
         Book(title: "The C Programming Language", author: "Kernighan", cover: "book4", year: 1988, selected: false),
         Book(title: "Being Digital", author: "Negroponte", cover: "book5", year: 1996, selected: false),
         Book(title: "Only the Paranoid Survive", author: "Grove", cover: "book6", year: 1999, selected: false),
         Book(title: "Accidental Empires", author: "Cringely", cover: "book7", year: 1996, selected: false),
         Book(title: "Bobby Fischer Teaches Chess", author: "Fischer", cover: "book8", year: 1982, selected: false),
         Book(title: "New Guide to Science", author: "Asimov", cover: "book9", year: 1993, selected: false),
         Book(title: "Christine", author: "King", cover: "book10", year: 1983, selected: false),
         Book(title: "IT", author: "King", cover: "book11", year: 1987, selected: false),
         Book(title: "Ending Aging", author: "Grey", cover: "book12", year: 2007, selected: false)
      ]
   }
}