refac: missing user or article is reported with a domain not-found error instead of a raw GORM error, and the API answers 404 for it

internal/infrastructure/persistence/repositories/userRepository.go

@@ -21,7 +21,7 @@ func (u *UserRepository) Get(id uint32) (domainUser.User, error) {
 	var localUser entity.User
 	err := u.db.Model(&entity.User{}).First(&localUser, id).Error
 	if err != nil {
-		return domainUser.User{}, err
+		return domainUser.User{}, mapNotFoundErr(err, domainUser.ErrUserNotFound)
 	}
 
 	return mappers.UserToDomain(localUser), nil
@@ -69,7 +69,7 @@ func (u *UserRepository) GetByUsername(username string) (domainUser.User, error)
 	var localUser entity.User
 	err := u.db.Model(&entity.User{}).Where("username = ?", username).First(&localUser).Error
 	if err != nil {
-		return domainUser.User{}, err
+		return domainUser.User{}, mapNotFoundErr(err, domainUser.ErrUserNotFound)
 	}
 
 	return mappers.UserToDomain(localUser), nil
@@ -79,7 +79,7 @@ func (u *UserRepository) GetByEmail(email string) (domainUser.User, error) {
 	var localUser entity.User
 	err := u.db.Model(&entity.User{}).Where("email = ?", email).First(&localUser).Error
 	if err != nil {
-		return domainUser.User{}, err
+		return domainUser.User{}, mapNotFoundErr(err, domainUser.ErrUserNotFound)
 	}
 
 	return mappers.UserToDomain(localUser), nil