Canteen Management

Part 2 of the Dietetics/Nutrition workflow (Part 1: Admin backend, Redmine #388). New hospital-scoped DietTypesController (api/hr/diet-types) + thin IDietTypeService pass-through to IAdminServiceContract (diet types carry no HR-local data, unlike IDoctorService which enriches an Admin profile with HR employment data). HospitalId always resolved server-side from IHospitalContext, never trusted from the request body. Create request type deliberately omits Code case-normalisation -- IPD DietType enum values are PascalCase, and the force-uppercase mistake already broke this twice this session (Canteen local catalog, Admin draft entity). hr.diet_types.read/create/update/deactivate permission keys already seeded onto the HR Manager role in Admin (part of #388s commit). HR unit suite 1135/1135 green (4 new DietTypeService tests + existing AuthorizationCoverageTests confirms every new action is permission-gated).