implement graphQL and init postgres

local/repository/membership.go

@@ -22,12 +22,12 @@ func NewMembershipRepository(db *gorm.DB) *MembershipRepository {
 	}
 }
 
-// FindUserByUsername finds a user by their username.
+// FindUserByEmail finds a user by their email.
 // It preloads the user's role and the role's permissions.
-func (r *MembershipRepository) FindUserByUsername(ctx context.Context, username string) (*model.User, error) {
+func (r *MembershipRepository) FindUserByEmail(ctx context.Context, email string) (*model.User, error) {
 	var user model.User
 	db := r.db.WithContext(ctx)
-	err := db.Preload("Roles.Permissions").Where("username = ?", username).First(&user).Error
+	err := db.Preload("Roles.Permissions").Where("email = ?", email).First(&user).Error
 	if err != nil {
 		return nil, err
 	}