Implement bit-perfect feature in Shuttle 2

[timusus]

Implements bit-perfect audio playback for USB DACs on Android 14+ devices, addressing issue #157. This feature allows audio to be sent directly to external USB DACs without resampling, mixing, or processing by Android's audio system, preserving maximum audio quality for high-resolution files.

Changes:

• Add BitPerfectManager to detect USB DAC connections and configure bit-perfect mode using AudioMixerAttributes API
• Add MODIFY_AUDIO_SETTINGS permission required for audio configuration
• Add user preference toggle in Playback settings
• Integrate with existing playback architecture via dependency injection
• Automatically activates when USB DAC is connected and preference is enabled
• Requires Android 14 (API 34) or higher

The implementation monitors USB device attach/detach events and queries supported mixer attributes to configure the optimal bit-perfect playback mode for connected DACs.