Replace module-level audio functions with proper OOP API:
- mcrfpy.Sound: Wraps sf::SoundBuffer + sf::Sound for short effects
- mcrfpy.Music: Wraps sf::Music for streaming long tracks
- Both support: volume, loop, playing, duration, play/pause/stop
- Music adds position property for seeking
Add mcrfpy.keyboard singleton for real-time modifier state:
- shift, ctrl, alt, system properties (bool, read-only)
- Queries sf::Keyboard::isKeyPressed() directly
Add mcrfpy.__version__ = "1.0.0" for version identity
Remove old audio API entirely (no deprecation - unused in codebase):
- createSoundBuffer, loadMusic, playSound
- setMusicVolume, getMusicVolume, setSoundVolume, getSoundVolume
closes#66, closes#160, closes#164🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
