Replace the Python Control Board client with a native Go service that reads the PCA9554 input expander through the GPIO interrupt path, renders the 128x64 SSD1306 menu, and drives SCSI ID, image, profile, and system-action workflows through the PiSCSI daemon. Keep input handling latency-sensitive with bounded queues, debouncing, diagnostics, and a separate asynchronous menu, display, and network pipeline.
Add a Control Board command, service unit, cross-build targets, and comprehensive unit coverage. Consolidate common I2C, configuration/profile, host-information, command, and embedded-asset support under the shared Go packages; update the OLED client and web configuration code to use those shared components, and document Control Board prerequisites, build, run, diagnostic, and service setup.
The PiSCSI Control Board hardware and original Python client were created by Benjamin Zeiss (@bzeiss), and the Go client is a rewrite of that software.
