Fix audio clipping and add low-latency Speaker configuration

[BeanRepo]

Description

Audio Improvements:

• Fix Mixer Volume Range for Speaker and Microphone
• Add Low-Latency Configuration args for Speaker

This PR addresses audio issues in real-time synthesis WaveGenerator Brick and improves Speaker configurability.

Changes:

• Fix Mixer Volume Range: Corrects Speaker volume control to properly map 0-100% to actual hardware mixer ranges, preventing volume setting failures

• Add Real-Time Audio Configuration:
  Introduces periodsize and queue_maxsize parameters to Speaker peripeheral for optimal latency control:

  • periodsize: Aligns ALSA buffer with generation blocks (eliminates audio glitches in WaveGenerator)
  • queue_maxsize: Controls application queue depth for latency vs stability tradeoff

• WaveGenerator Enhancements:

  • Auto-configures internal Speaker with optimal real-time settings (periodsize aligned to block_duration)
  • Supports external-defined Speaker instances with ownership pattern and validation warnings
  • Default device changed to USB_SPEAKER_1 for clarity

• Documentation Updates:

  • READMEs and examples updated to reflect new parameters and external Speaker lifecycle management

Fixes:

• Audio clipping in theremin app caused by buffer periodsize mismatch between ALSA, Speaker and WaveGenerator buffers.

Tests:

• All Speaker and WaveGenerator tests passing
• Real tests on theremin-simulator app passed with 2 available speaker headset.