use-case-test

Writes the tests for a use case (UC-XXX) by running the test skills recorded in docs/architecture/stack.md from the integration layer up — looked up in its Integration layer table for the entry layer the use case is offered through — plus E2E per the E2E scope; a lower layer gets tests only as a second entry layer or when named. Owns the rules every test layer shares: the specification is the oracle, a test that disagrees with the code stays failing, existing tests are reconciled rather than duplicated, and every test carries the use case id. Use when the user asks to "test UC-001", "write the tests for this use case", "test only the service layer", or mentions tests for a use case in a project that combines layer plugins (aiup-jooq, aiup-jpa, aiup-spring-boot, aiup-vaadin, aiup-angular, aiup-playwright). With a combined stack plugin (aiup-vaadin-jooq, aiup-angular-jpa, aiup-blazor-dotnet, aiup-nestjs-nextjs), use its test skills. A TC-* journey is /test-case-implement; a TC-*.md document is /test-case.