import { Lesson } from './types';
export interface LintIssue {
    /** Step index the issue is about, or -1 for lesson-level issues. */
    step: number;
    /** Severity: `error` breaks the contract; `warn` is a smell. */
    level: 'error' | 'warn';
    message: string;
}
/**
 * Lint one lesson. `errors` block a usable lesson (no anchor / no expect / no
 * hint); `warn`s flag likely-unintended authoring. Optionally pass `hasI18nKey`
 * (e.g. `i18n.exists`) to check that instruction/hint/title keys resolve.
 */
export declare const lintLesson: (lesson: Lesson, hasI18nKey?: (key: string) => boolean) => LintIssue[];
/** Convenience: does the lesson have any `error`-level issues? */
export declare const isLessonValid: (lesson: Lesson) => boolean;