Implements the UI layer of a use case (UC-XXX) as an Angular client: standalone page and presentational components, signal() state, one hand-written HttpClient service per entity with TypeScript models that match the API layer's DTOs field by field, and routes in app.routes.ts. Consumes the Handover of the API layer (endpoints, DTOs) and checks the JSON contract against it. Use when the user asks to "build the Angular page", "implement the UI of UC-001", "create the Angular component", "wire the frontend to the REST API", or mentions Angular, standalone components, signals, or an Angular client calling a backend. Normally run by /use-case-implement as the UI layer of a project whose docs/architecture/stack.md names Angular; it can also be run directly. Does not write tests — that is /angular-ui-test.