package domain import "errors" var ( ErrNotFound = errors.New("resource not found") ErrForbidden = errors.New("user does not have permission") ErrBadRequest = errors.New("invalid input") ErrConflict = errors.New("resource conflict (e.g., duplicate)") ErrUnauthorized = errors.New("authentication required or failed") ErrInternalServer = errors.New("internal server error") ErrValidation = errors.New("validation failed") )