[FIX] Initialize required User fields explicitly during registration

- Set Role to 'user' explicitly
- Set IsActive to true explicitly
- Set IsVerified to false explicitly
- Prevents database constraint errors when creating new users
- Ensures all required fields are set even if database defaults are missing

veza-backend-api/internal/core/auth/service.go

@@ -120,7 +120,9 @@ func (s *AuthService) Register(ctx context.Context, email, username, password st
 		Username:     username,
 		Slug:         strings.ToLower(username),
 		PasswordHash: string(hashedPassword),
-		// IsVerified: false par défaut
+		Role:         "user",     // Valeur par défaut
+		IsActive:     true,       // Valeur par défaut
+		IsVerified:   false,     // Valeur par défaut
 	}
 
 	if err := s.db.WithContext(ctx).Create(user).Error; err != nil {