Refactor entities: remove preprocessor blocks, unify style

Refactored Envelope, Receiver, and Signature entity classes to eliminate preprocessor directives around class and property definitions. Applied attributes directly and reformatted properties for clarity. Constructors are now always present, with default initializations still conditional where needed. Removed obsolete directives from IHasAddedWho. These changes improve code readability, maintainability, and cross-platform compatibility.

EnvelopeGenerator.Domain/Entities/Envelope.cs

@@ -5,19 +5,13 @@ using System.ComponentModel.DataAnnotations;
 using System.ComponentModel.DataAnnotations.Schema;
 using EnvelopeGenerator.Domain.Constants;
 using Newtonsoft.Json;
-
 #if NETFRAMEWORK
 using System.Collections.Generic;
 using System.Linq;
 #endif
 
 namespace EnvelopeGenerator.Domain.Entities
-#if NET
-    ;
-#elif NETFRAMEWORK
 {
-#endif
-
     [Table("TBSIG_ENVELOPE", Schema = "dbo")]
     public class Envelope : IHasAddedWhen, IHasChangedWhen
     {
@@ -81,7 +75,8 @@ public class Envelope : IHasAddedWhen, IHasChangedWhen
 #if nullable
         ?
 #endif
-        Title { get; set; }
+            Title
+        { get; set; }
 
         [Column("COMMENT", TypeName = "nvarchar(128)")]
         public string Comment { get; set; }
@@ -146,14 +141,16 @@ public class Envelope : IHasAddedWhen, IHasChangedWhen
 #if nullable
         ?
 #endif
-        DocResult { get; set; }
+            DocResult
+        { get; set; }
 
         [ForeignKey("EnvelopeTypeId")]
         public virtual EnvelopeType
 #if nullable
         ?
 #endif
-        Type { get; set; }
+            Type
+        { get; set; }
 
 #if NETFRAMEWORK
         [NotMapped]
@@ -167,19 +164,22 @@ public class Envelope : IHasAddedWhen, IHasChangedWhen
 #if nullable
         ?
 #endif
-        Documents { get; set; }
+            Documents
+        { get; set; }
 
         public List<History>
 #if nullable
         ?
 #endif
-        Histories { get; set; }
+            Histories
+        { get; set; }
 
         public List<EnvelopeReceiver>
 #if nullable
         ?
 #endif
-        EnvelopeReceivers { get; set; }
+            EnvelopeReceivers
+        { get; set; }
 
         //#if NETFRAMEWORK
         /// <summary>
@@ -202,7 +202,4 @@ public class Envelope : IHasAddedWhen, IHasChangedWhen
         }
         //#endif
     }
-
-#if NETFRAMEWORK
 }
-#endif

EnvelopeGenerator.Domain/Entities/Receiver.cs

@@ -1,19 +1,13 @@
-using System;
+using EnvelopeGenerator.Domain.Interfaces;
-using EnvelopeGenerator.Domain.Interfaces;
 using System.ComponentModel.DataAnnotations;
 using System.ComponentModel.DataAnnotations.Schema;
-using System.Drawing;
 #if NETFRAMEWORK
+using System;
 using System.Collections.Generic;
 #endif
 
 namespace EnvelopeGenerator.Domain.Entities
-#if NET
-    ;
-#elif NETFRAMEWORK
 {
-#endif
-
     [Table("TBSIG_RECEIVER", Schema = "dbo")]
     public class Receiver : IHasAddedWhen
     {
@@ -45,7 +39,4 @@ public class Receiver : IHasAddedWhen
 
         public string GetSignature() => EmailAddress.ToUpperInvariant().GetChecksum();
     }
-
-#if NETFRAMEWORK
 }
-#endif

EnvelopeGenerator.Domain/Entities/Signature.cs

@@ -8,12 +8,7 @@ using System.Collections.Generic;
 #endif
 
 namespace EnvelopeGenerator.Domain.Entities
-#if NET
-    ;
-#elif NETFRAMEWORK
 {
-#endif
-
     [Table("TBSIG_DOCUMENT_RECEIVER_ELEMENT", Schema = "dbo")]
     public class Signature : ISignature, IHasReceiver, IHasAddedWhen, IHasChangedWhen, IHasChangedWho
     {
@@ -102,7 +97,8 @@ public class Signature : ISignature, IHasReceiver, IHasAddedWhen, IHasChangedWhe
 #if nullable
         ?
 #endif
-        ChangedWho { get; set; }
+            ChangedWho
+        { get; set; }
 
         [ForeignKey("DocumentId")]
         public virtual Document Document { get; set; }
@@ -112,13 +108,15 @@ public class Signature : ISignature, IHasReceiver, IHasAddedWhen, IHasChangedWhe
 #if nullable
         ?
 #endif
-        Receiver { get; set; }
+            Receiver
+        { get; set; }
 
         public virtual IEnumerable<ElementAnnotation>
 #if nullable
         ?
 #endif
-        Annotations { get; set; }
+            Annotations
+        { get; set; }
 
 #if NETFRAMEWORK
         [NotMapped]
@@ -128,7 +126,4 @@ public class Signature : ISignature, IHasReceiver, IHasAddedWhen, IHasChangedWhe
         public double Left => Math.Round(X, 5);
 #endif
     }
-
-#if NETFRAMEWORK
 }
-#endif

EnvelopeGenerator.Domain/Interfaces/IHasAddedWho.cs

@@ -1,7 +1,3 @@
-#if NETFRAMEWORK
-using System;
-#endif
-
 namespace EnvelopeGenerator.Domain.Interfaces
 {
     public interface IHasAddedWho