cleanup some shit in auth service

internal/auth/service/auth.go

@@ -36,7 +36,6 @@ func NewAuthService(repo UserRepository, jwtSecret string) *AuthService {
 }
 
 func (s *AuthService) SignUp(ctx context.Context, email, username, password string) (string, error) {
-	// Check if user already exists
 	_, err := s.repo.GetByEmail(ctx, email)
 	if err == nil {
 		return "", domain.ErrUserAlreadyExists
@@ -45,13 +44,11 @@ func (s *AuthService) SignUp(ctx context.Context, email, username, password stri
 		return "", err
 	}
 
-	// Hash password
 	hashedPassword, err := bcrypt.GenerateFromPassword([]byte(password), bcryptCost)
 	if err != nil {
 		return "", err
 	}
 
-	// Create user
 	user := &domain.User{
 		ID:       domain.NewID(),
 		Email:    email,
@@ -63,7 +60,6 @@ func (s *AuthService) SignUp(ctx context.Context, email, username, password stri
 		return "", err
 	}
 
-	// Generate token
 	token, err := s.generateToken(user)
 	if err != nil {
 		return "", err
@@ -73,7 +69,6 @@ func (s *AuthService) SignUp(ctx context.Context, email, username, password stri
 }
 
 func (s *AuthService) SignIn(ctx context.Context, email, password string) (string, error) {
-	// Get user by email
 	user, err := s.repo.GetByEmail(ctx, email)
 	if err != nil {
 		if err == domain.ErrUserNotFound {
@@ -82,12 +77,10 @@ func (s *AuthService) SignIn(ctx context.Context, email, password string) (strin
 		return "", err
 	}
 
-	// Check password
 	if err := bcrypt.CompareHashAndPassword([]byte(user.Password), []byte(password)); err != nil {
 		return "", domain.ErrInvalidPassword
 	}
 
-	// Generate token
 	token, err := s.generateToken(user)
 	if err != nil {
 		return "", err