TariqDaCoder/brew-and-bite-cafe

AI Summary: Implement a 'Back' or 'Switch Role' button in a JavaFX application to allow users to navigate back to the role selection screen from the Customer, Barista, or Manager views. This button should maintain the application's shared data (order queue, inventory) across role changes, preventing data loss when switching roles. The solution should be branched from the `feat-Observer-pattern-14` branch.