Improve error handling in InsertObjectProcedureHandler

Wrap SQL execution in try-catch and inject SqlExceptionOptions.
Throw BadRequestException with a clear message when insert fails due to missing referenced entities, based on SqlException number. Other SQL exceptions are rethrown. This provides better feedback for foreign key/reference errors.

src/ReC.Application/Common/Procedures/InsertProcedure/InsertObjectProcedure.cs

@@ -1,4 +1,5 @@
 using DigitalData.Core.Abstraction.Application.Repository;
+using DigitalData.Core.Exceptions;
 using MediatR;
 using Microsoft.Data.SqlClient;
 using ReC.Application.Common.Exceptions;
@@ -7,6 +8,7 @@ using ReC.Application.EndpointParams.Commands;
 using ReC.Application.Endpoints.Commands;
 using ReC.Application.Results.Commands;
 using ReC.Application.Profile.Commands;
+using ReC.Application.Common.Options;
 
 namespace ReC.Application.Common.Procedures.InsertProcedure;
 
@@ -41,7 +43,7 @@ public static class InsertObjectProcedureExtensions
     }
 }
 
-public class InsertObjectProcedureHandler(IRepository repo) : IRequestHandler<InsertObjectProcedure, long>
+public class InsertObjectProcedureHandler(IRepository repo, SqlExceptionOptions sqlExceptionOptions) : IRequestHandler<InsertObjectProcedure, long>
 {
     public async Task<long> Handle(InsertObjectProcedure request, CancellationToken cancel)
     {
@@ -110,6 +112,8 @@ public class InsertObjectProcedureHandler(IRepository repo) : IRequestHandler<In
             }
         };
 
+        try
+        {
             await repo.ExecuteQueryRawAsync(
                 "EXEC [dbo].[PRREC_INSERT_OBJECT] " +
                 "@pENTITY, @pADDED_WHO, @pADDED_WHEN, " +
@@ -122,6 +126,17 @@ public class InsertObjectProcedureHandler(IRepository repo) : IRequestHandler<In
                 "@oGUID OUTPUT",
                 parameters,
                 cancel);
+        }
+        catch (SqlException ex)
+        {
+            if (sqlExceptionOptions.SqlExceptionNumber.Contains(ex.Number))
+                throw new BadRequestException(
+                    $"Insert '{request.Entity}' failed because one or more referenced entities do not exist. " +
+                    "Please verify the supplied identifiers and try again.\n" +
+                    ex.Message, ex);
+            else
+                throw;
+        }
 
         var guidParam = parameters.Last();