Add ReadOnly property to Envelope class

Added a ReadOnly property to the Envelope class that returns true when EnvelopeTypeId is 2. The property is marked with [JsonIgnore] and [NotMapped] to exclude it from JSON serialization and database mapping.

EnvelopeGenerator.Domain/Entities/Envelope.cs

@@ -108,6 +108,10 @@ public class Envelope
     [Column("ENVELOPE_TYPE")]
     public int? EnvelopeTypeId { get; set; }
 
+    [JsonIgnore]
+    [NotMapped]
+    public bool ReadOnly => EnvelopeTypeId == 2;
+    
     [Column("CERTIFICATION_TYPE")]
     public int? CertificationType { get; set; }