Move hw-esp32-gpio and hw-rp2040-gpio into hw-gpio/ports/esp32/
and hw-gpio/ports/rp2040/ using the new ports build system.
Co-authored-by: Claude <noreply@anthropic.com>
Add three new gems for GPIO pin control:
- hw-gpio: common Ruby API, C bindings, and HAL header
- hw-esp32-gpio: ESP32 HAL using ESP-IDF GPIO driver
- hw-rp2040-gpio: RP2040 HAL using Pico SDK
Co-authored-by: Claude <noreply@anthropic.com>