Class NocturnaAudio

NocturnaAudio manages all audio playback in Nocturna using Babylon.js's audio engine.

Responsibilities:

• Implements the singleton pattern to ensure only one audio manager exists.
• Initializes and unlocks the Babylon.js audio engine.
• Handles background music playback, including play, stop, resume, mute, and volume control.
• Ensures background music is properly disposed and replaced when changed.

Usage:

• Use await NocturnaAudio.getInstance() to get the singleton instance.
• Use setBackgroundMusic to play or change background music.
• Use muteBackgroundMusic, stopBackgroundMusic, resumeBackgroundMusic, and setVolume for playback control.