Update BOT_SETUP.md with full retro mode combo reference, scoring, and strategy tips. Add docs/bot-guide.md as a standalone developer guide covering all challenge types including retro mode. Add docs/sprite-guide.md and sprite-reference.html for custom sprite creation. Update docs.ts API endpoint and Python example bot with retro_mode handling. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>