Backend login and register

src/Application/Interfaces/IJwtService.cs

@@ -0,0 +1,10 @@
+using Domain.Entities;
+
+namespace Application.Interfaces;
+
+public interface IJwtService
+{
+    Task<string> GenerateTokenAsync(User user);
+    Task<string> GenerateAndSaveRefreshTokenAsync(User user);
+    Task<User?> ValidateRefreshTokenAsync(int userId, string refreshToken);
+}