/** 云集合 `learning_plans` 文档（§3.9）；weeks 结构与后端 WeekPlan[] 一致，此处用 unknown[] 保持 core 零依赖 */
export interface LearningPlanRecord {
    _id: string;
    ageMin: number;
    ageMax: number;
    ageLabel: string;
    milestones: string[];
    weeks: unknown[];
}