Explain a codebase or repository in human terms so the user truly understands it — what it does, what makes it special, similar systems, prerequisite concepts — then quiz the user and verify their understanding. Use whenever the user says "explain this repo/codebase", "help me understand this project", "walk me through this code", "what is special about X repo", or wants to learn a system deeply. Do NOT use for rewriting text to sound human — that is the humanizer skill.
