fix: 全部TS错误修复(25->0) + 证书API 500修复 + i18n缺失key补全 + 类型定义修正

- 证书API 500修复: AssessmentCertificate实体注册到app.module.ts
- 前端TS错误25个清零: i18n key 17个, 类型定义8个
- i18n补全: 17个缺失key添加到zh/en/ja
- KnowledgeFile类型: 添加title, content字段
- importService: 改用apiClient.request替代raw fetch
- ModeSelector: 移除jsx prop
- questionBankService: .ok -> .status >= 400
- NotebookDetailView: .filter -> .items.filter
- ImportTasksDrawer: tasks.items提取
- API端点审计: 16/16通过
- 数据库Schema审计: 25表288列一致
- AGENTS.md更新

web/services/importService.ts

@@ -48,7 +48,7 @@ export const importService = {
     },
 
     delete: async (token: string, id: string): Promise<void> => {
-        const response = await fetch(`${API_BASE_URL}/import-tasks/${id}`, {
+        const response = await apiClient.request(`/import-tasks/${id}`, {
             method: 'DELETE',
             headers: {
                 'Authorization': `Bearer ${token}`