riverdi/riverdi-eve — reverse-engineered prompt

Build me a C library plus demo app for a Riverdi Intelligent Display using Bridgetek EVE graphics controllers. I want a simple starting point where I can edit one demo file to draw screens, text, buttons, and other EVE commands without dealing with all the SPI details every time.

Please support the common EVE families like FT800, FT801, FT810, FT811, FT812, FT813, BT815, BT816, BT817, and BT818. Structure the code in clear layers so the app calls friendly graphics functions, the EVE layer handles the controller registers and command FIFO, and the host layer hides the board specific SPI, chip select, and power control code.

Include build files for Raspberry Pi, STM32 f0, STM32 f4, and Windows with an FT232H USB SPI adapter. Add a small demo that initializes the display and shows a basic screen. Please include clear build notes and comments so someone can port the host layer to another board later.