API Instructions

• Keep Nest features layered: controllers map HTTP, services own business logic, repositories own persistence and queries.
• Follow the existing feature structure: *.controller.ts, *.service.ts, *.repository.ts, dto/, and *.module.ts.
• Validate inbound request data at the DTO boundary using the existing Nest validation patterns.
• Keep HTTP concerns at the edge. Services may raise domain errors; controllers and filters should translate them into HTTP responses.
• When endpoint behavior or request/response contracts change, update the relevant unit or e2e tests.