Add EF Core data annotations for table and FK mapping

Added [Table] and [ForeignKey] attributes to entity classes to explicitly map them to database tables/views and define relationships. Updated using directives as needed. Improves entity mapping clarity and robustness against schema changes.

src/ReC.Domain/Entities/Connection.cs

@@ -1,5 +1,8 @@
-namespace ReC.Domain.Entities;
+using System.ComponentModel.DataAnnotations.Schema;
 
+namespace ReC.Domain.Entities;
+
+[Table("TBDD_CONNECTION")]
 public class Connection
 {
     public short? Id { get; set; }