first commit

Models/PairingCode.cs

@@ -0,0 +1,20 @@
+using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations.Schema;
+using Microsoft.EntityFrameworkCore;
+
+namespace Fitness_core_BE.Models
+{
+    [Index(nameof(Code))]
+    public class PairingCode
+    {
+        [Key]
+        public Guid Id { get; set; }
+        public string Code { get; set; }
+        public Guid FKClientId { get; set; }
+        [ForeignKey("FKClientId")]
+        public Client Client { get; set; }
+        public DateTime ExpiresAt { get; set; }
+        public bool IsUsed { get; set; } = false;
+        public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
+    }
+}