FlagIQ: Master World Flags

1) Improved login and registration forms to support browser and device password managers, allowing players to save and autofill their login details more easily in future. 2) Added tracking for guest players and total app users, allowing better visibility of players who use the app without creating an account. 3) Improved user tracking so guest activity can be linked to an account if a player registers later, preventing loss of progress and reducing duplicate counts. 4) Removed lock icons from locked levels for a cleaner level selection screen. 5) Added a 2-second display of the correct answer after successful selections, making it easier to learn and review flags. 6) Ensured Time Trial mode timers continue counting down during the correct-answer display period. 7) Removed hearts/lives from the in-game header to reduce confusion with timers and improve gameplay clarity.