- Add python-dotenv support to control_server.py and sound.py
- Load TRANSPORT from environment variable (default: spi)
- Load AUDIO_INPUT_DEVICE from environment variable (default: 7)
- Load all port configurations from environment variables
- Update .env.example with comprehensive configuration options
- Create .env file with sensible defaults for Pi
- Transport, sound device, and network settings now configurable via .env
- ESP32-C3 SPI slave project with ESP-NOW broadcast functionality
- Raspberry Pi SPI master test tools and CLI for JSON communication
- Merged src/ directory from full branch with lighting controller code
- Updated Pipfile with system install scripts and ESP32 monitoring
- Added comprehensive test suite for SPI communication
