ExecPlan — Lifecycle Management Announce at start: "Using the exec-plan skill." What is an ExecPlan A self-contained, living document that a fresh agent session can follow to deliver observable, working behavior. Lives in . The format follows the specification in . An ExecPlan is NOT a todo list. It is a narrative that tells the story of a change: why it matters, what the codebase looks like now, what it should look like after, and how to prove it worked. When to use this skill - Required for multi-step or multi-file work, new features, refactors, or tasks expected to take more than about an…