VMU Integration

d3tui_vmu_t* d3tui_vmu_init(int port, int vmu_slot);
void d3tui_vmu_destroy(d3tui_vmu_t* vmu);
void d3tui_vmu_clear(d3tui_vmu_t* vmu, uint8_t color);
void d3tui_vmu_draw_pixel(d3tui_vmu_t* vmu, int x, int y, uint8_t color);
void d3tui_vmu_draw_text(d3tui_vmu_t* vmu, int x, int y, const char* text);
void d3tui_vmu_sync(d3tui_vmu_t* vmu);
void d3tui_vmu_set_contrast(d3tui_vmu_t* vmu, int level);

VMU (Visual Memory Unit) auxiliary display support. The VMU screen is 48x32 pixels with 6x8 pixel font.