Commit MWS backend source tree

The ASP.NET Core solution (mws.api/mws.application/mws.domain/
mws.infrastructure) existed only as untracked working files. Adding
it to version control, plus a .gitignore for build output and local
tooling directories, so the CQRS/mediator refactor plan has a real
git history to branch and diff against.

mws.application/Auth/AuthService.cs

@@ -0,0 +1,35 @@
+using AutoMapper;
+using Mws.Application.Common;
+
+namespace Mws.Application.Auth;
+
+public interface IAuthService
+{
+    Task<LoginResponse> LoginAsync(LoginRequest request, CancellationToken cancellationToken = default);
+}
+
+public class AuthService(IUnitOfWork uow, IPasswordHasher passwordHasher, ITokenService tokenService, IMapper mapper)
+    : IAuthService
+{
+    public async Task<LoginResponse> LoginAsync(LoginRequest request, CancellationToken cancellationToken = default)
+    {
+        var username = request.Username.Trim();
+        var user = await uow.Users.GetByUsernameWithRoleAsync(username, cancellationToken);
+
+        if (user is null || !passwordHasher.Verify(request.Password, user.PasswordHash))
+        {
+            throw new UnauthorizedException("Invalid username or password");
+        }
+
+        if (!user.IsActive)
+        {
+            throw new ForbiddenException("Account disabled");
+        }
+
+        return new LoginResponse
+        {
+            Token = tokenService.CreateToken(user.Id, user.Username),
+            User = mapper.Map<UserDto>(user),
+        };
+    }
+}