Execute an approved Plan spec from spec slug or GitHub URL through implementation, checks, commit, push, and a ready pull request. Use this skill whenever the user says `$plan-execute`, asks to execute or implement a Plan spec, provides a Plan spec slug, asks for a spec-to-PR workflow, or asks to turn an approved planning issue/spec into code.
Use this skill when working with a project-local `plan` workspace that keeps planning material under `.plan/`. Focus on brainstorms, idea docs, specs, execution slices, legacy compatibility surfaces, and roadmap updates.