Implement data persistence and main menu UI  

- Introduce DataManager singleton to persist high score via JSON save/load. 

- Add MenuUIHandler to capture player name and handle game start. 

- Wire MainManager to display/update BestScoreText and call DataManager.UpdateHighScore. 

- Add new script files, meta files, and update StartMenu and Main scenes. 

- Clean up unused using directives across several scripts. 

- Update DefaultVolumeProfile and EditorBuildSettings.

Classic Unity-powered arcade game where players control a paddle to deflect a bouncing ball and shatter rows of colored bricks to score points and beat the high score.