重构：认证体系规范，前端API类型新增prerequisite字段

- CertificationType 接口新增 prerequisite 字段
- 转换函数新增 prerequisite 字段映射
- 配合后端认证体系重构（L1→L2→L3递进关系）

console/src/api/modules/certification.ts

@@ -17,6 +17,7 @@ export interface CertificationType {
   badgeColor: string;
   sortOrder: number;
   isActive: boolean;
+  prerequisite: string; // 前置认证类型code，空=无前置要求
   // 技能认证附带用户最佳成绩
   myBestScore?: number;
   myBestLevel?: string;
@@ -136,6 +137,7 @@ function mapCertType(raw: Record<string, any>): CertificationType {
     badgeColor: raw.badge_color || "#9BBBF4",
     sortOrder: raw.sort_order || 0,
     isActive: raw.is_active !== false,
+    prerequisite: raw.prerequisite || "",
     myBestScore: raw.my_best_score,
     myBestLevel: raw.my_best_level,
   };