Apply this skill whenever designing, scaffolding, reviewing, or refactoring the architecture of a Next.js App Router + TypeScript + Tailwind + shadcn + Drizzle application. Triggers on requests like "how should I structure this", "where should this logic live", "scaffold a new feature", "review my folder structure", "plan this feature", "add a new module", or any time you're creating multiple files that need to fit together coherently. Use this skill proactively — do not make ad-hoc structural decisions without consulting it.