docs: add comprehensive SDL2 frontend compatibility analysis#53

eddmann wants to merge 3 commits intomaineddmann/phpboy:mainfrom

claude/review-php-sdl2-compatibility-01KhnzHo5k6ES4gAQTkSFvwCeddmann/phpboy:claude/review-php-sdl2-compatibility-01KhnzHo5k6ES4gAQTkSFvwCCopy head branch name to clipboard