Add ESP32-C3 SPI slave with ESP-NOW, Raspberry Pi test tools, and updated project structure

- 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

test/setup_spi.sh

@@ -0,0 +1,33 @@
+#!/bin/bash
+# Setup script for SPI testing on Raspberry Pi
+
+echo "Setting up SPI for testing..."
+
+# Enable SPI interface
+echo "Enabling SPI interface..."
+sudo raspi-config nonint do_spi 0
+
+# Install required packages
+echo "Installing required packages..."
+sudo apt update
+sudo apt install -y python3-spidev python3-pip
+
+# Install Python dependencies using pipenv
+echo "Installing Python dependencies with pipenv..."
+cd ..
+pipenv install
+
+# Check SPI devices
+echo "Checking SPI devices..."
+ls -la /dev/spi*
+
+# Show GPIO configuration
+echo "GPIO Configuration:"
+echo "  SCK:  GPIO11 (Physical pin 23)"
+echo "  MISO: GPIO9  (Physical pin 21)"
+echo "  MOSI: GPIO10 (Physical pin 19)"
+echo "  CS:   GPIO8  (Physical pin 24)"
+
+echo "Setup complete!"
+echo "Run send-json with:"
+echo "  pipenv run send-json --beat --brightness 128"