Groove Work Exec

This is the execution stage of the Groove workflow. It picks up after you've run the planning skill, writes the actual code and tests according to that plan, and logs progress to your task backend as dated notes. The skill checks your `.groove/index.md` for the backend config and creates a work stage task automatically. What I like here is the constraint that explicitly tells Claude not to mark tasks complete during execution, that happens in the review stage. If you try to run this without a plan first, it warns you and asks for confirmation. It's opinionated about the workflow sequence, which is exactly what you want from a process skill.