Add Endpoint entity class for database mapping

Introduced a new `Endpoint` class in the `ReC.Domain.Entities` namespace to represent the `TBREC_CFG_ENDPOINT` database table.

- Added Entity Framework annotations to map properties to database columns.
- Defined properties for `Id`, `Active`, `Description`, `Uri`, `AddedWho`, `AddedWhen`, `ChangedWho`, and `ChangedWhen`.
- Configured `Id` as the primary key with auto-generated values.

src/ReC.Domain/Entities/Endpoint.cs

@@ -0,0 +1,35 @@
+using System;
+using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations.Schema;
+
+namespace ReC.Domain.Entities;
+
+[Table("TBREC_CFG_ENDPOINT")]
+public class Endpoint
+{
+    [Key]
+    [Column("GUID")]
+    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
+    public long? Id { get; set; }
+
+    [Column("ACTIVE")]
+    public bool? Active { get; set; }
+
+    [Column("DESCRIPTION")]
+    public string? Description { get; set; }
+
+    [Column("URI")]
+    public string? Uri { get; set; }
+
+    [Column("ADDED_WHO")]
+    public string? AddedWho { get; set; }
+
+    [Column("ADDED_WHEN")]
+    public DateTime? AddedWhen { get; set; }
+
+    [Column("CHANGED_WHO")]
+    public string? ChangedWho { get; set; }
+
+    [Column("CHANGED_WHEN")]
+    public DateTime? ChangedWhen { get; set; }
+}