Refactor AddedWho assignment in InsertObjectProcedure

AddedWho is now set via the AddedBy method instead of direct assignment in object initializers. The property is made internal with a private setter to prevent external modification. All ToObjectProcedure methods in insert procedure records are updated to use AddedBy for consistency and encapsulation.

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

@@ -12,7 +12,13 @@ public record InsertObjectProcedure : IRequest<long>
     /// </summary>
     public string Entity { get; set; } = null!;
 
-    public string? AddedWho { get; set; }
+    internal string? AddedWho { get; private set; }
+
+    public InsertObjectProcedure AddedBy(string addedWho)
+    {
+        AddedWho = addedWho;
+        return this;
+    }
 
     public InsertActionProcedure Action { get; set; } = new();
     public InsertEndpointProcedure Endpoint { get; set; } = new();