- use lv_display_get_*_resolution to compute available area
- apply lv_image_set_scale 2x/3x + pivot center when display large enough
- removes previous comment hack 'avoid non-exported LVGL transform symbols'
- now requires firmware feature/gameboy-canvas-full-api (symbols exported)
SDK: 0.8.0-dev built with IDF 5.5.2, 0 missing symbols