implement-senior
Cross-module coordination WITHIN an approved architect plan. May refactor internals across modules, add private helpers that span modules, and reorganize file layouts when the plan authorizes it. May NOT introduce new modules, new architectural patterns, new public contracts outside the plan, or new deps. Use when the architect plan explicitly covers multi-module work and the implementer needs to coordinate across them. Do NOT use for one-module work (route to `/safer:implement-junior`) or for introducing new modules/deps (route to `/safer:implement-staff`).