--- "mattpocock-skills": minor --- Rename the skill taxonomy from **Commands / Skills** to **User-invoked / Model-invoked** across the docs, and add `docs/invocation.md` defining the split: user-invoked skills are reachable only when you type them and exist to orchestrate; model-invoked skills can also be reached automatically when the task fits. A user-invoked skill may invoke model-invoked skills, but never another user-invoked one.