Mark ObtainEndpointCommand and mapping as obsolete

Mark ObtainEndpointCommand, its handler, and related mapping
profile as [Obsolete] with guidance to use the new procedure
or view-based approach. This deprecates the old command and
mapping logic in favor of updated patterns.

src/ReC.Application/Endpoints/MappingProfile.cs

@@ -6,6 +6,7 @@ namespace ReC.Application.Endpoints;
 // TODO: update to inject AddedWho from the current host/user contex
 public class MappingProfile : AutoMapper.Profile
 {
+    [Obsolete("Use the related procedure or view.")]
     public MappingProfile()
     {
         CreateMap<ObtainEndpointCommand, EndpointDto>()