Groove Work Doc

This generates "how does X work" documentation for parts of your codebase, aimed at future maintainers and AI agents who need to understand what's going on. It creates structured markdown files in `.groove/memory/docs/` with four sections: what the component does, which files matter, how the logic flows step by step, and gotchas that aren't obvious from skimming code. The skill uses an exploration agent to map the actual codebase first, so you get real file paths and execution traces instead of generic handwaving. Useful when onboarding someone new or when you keep forgetting how that one subsystem actually works.