Variable NavigationButtonsConst

Navigation Buttons Component Provides action buttons for replay and menu navigation.

This component delegates visual styling and accessibility behavior to BaseButtonOverlayHtml, providing:

• Consistent Korean / English bilingual theming
• Centralized button behavior and standard browser keyboard support
• Reduced code duplication (113 lines saved: 237 → 124)

Note: Audio callbacks are passed as props since this component is rendered inside a Canvas Html portal which doesn't have access to AudioProvider context.