Add EndpointAuth entity for database table mapping

Introduced the `EndpointAuth` class in the `ReC.Domain.Entities` namespace to represent the `TBREC_CFG_ENDPOINT_AUTH` database table.

- Added Entity Framework annotations for table and column mappings.
- Defined properties for all table columns, including `Id`, `Active`, `Description`, `Type`, `ApiKey`, `ApiValue`, `ApiKeyAddTo`, `Token`, `Username`, `Password`, `Domain`, `Workstation`, `AddedWho`, `AddedWhen`, `ChangedWho`, and `ChangedWhen`.
- Configured `Id` as the primary key with auto-generated values.

src/ReC.Domain/Entities/EndpointAuth.cs

@@ -0,0 +1,59 @@
+using System;
+using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations.Schema;
+
+namespace ReC.Domain.Entities;
+
+[Table("TBREC_CFG_ENDPOINT_AUTH")]
+public class EndpointAuth
+{
+    [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("TYPE")]
+    public string? Type { get; set; }
+
+    [Column("API_KEY")]
+    public string? ApiKey { get; set; }
+
+    [Column("API_VALUE")]
+    public string? ApiValue { get; set; }
+
+    [Column("API_KEY_ADD_TO")]
+    public string? ApiKeyAddTo { get; set; }
+
+    [Column("TOKEN")]
+    public string? Token { get; set; }
+
+    [Column("USERNAME")]
+    public string? Username { get; set; }
+
+    [Column("PASSWORD")]
+    public string? Password { get; set; }
+
+    [Column("DOMAIN")]
+    public string? Domain { get; set; }
+
+    [Column("WORKSTATION")]
+    public string? Workstation { 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; }
+}