Rename Guid property to Id in EndpointParam class

The `Guid` property in the `EndpointParam` class was renamed to `Id` to improve code readability and align with naming conventions. The `[Key]` and `[Column("GUID")]` attributes remain unchanged, ensuring the database schema mapping and primary key designation are preserved.

src/ReC.Domain/Entities/EndpointParam.cs

@@ -13,7 +13,7 @@ public class EndpointParam
 {
     [Key]
     [Column("GUID")]
-    public long? Guid { get; set; }
+    public long? Id { get; set; }
 
     [Column("ACTIVE")]
     public bool? Active { get; set; }