use-case-implement

Implements a use case (UC-XXX) across the technical layers of the project by running the layer skills recorded in docs/architecture/stack.md bottom-up — migration, persistence, service, API, UI, limited to the entry layers its **Layers:** line names — after checking the specification's status, reading exactly the requirements the use case links, reconciling an existing implementation. Owns the shared rules: no assumptions for specification gaps (recorded in docs/open-questions.md), decision rights, UC-XXX BR-YYY markers, no edits to tests or docs. Use when the user asks to "implement UC-001", "build this use case", "implement the use case end to end", "implement only the API layer of UC-001", or mentions implementing a use case in a project that combines layer plugins (aiup-flyway, aiup-jooq, aiup-jpa, aiup-spring-boot, aiup-vaadin, aiup-angular). For a project that uses a combined stack plugin (aiup-vaadin-jooq, aiup-angular-jpa, aiup-blazor-dotnet, aiup-nestjs-nextjs), use that plugin's /implement instead.