家长端结构化题目编辑器:题型联动表单替代 JSON 文本域,应用题支持 judgeMode 切换

- 新增 question-list.tsx:结构化题目卡片列表(选择题/判断题/填空题/应用题)
- 新增 question-list.test.tsx:4 个 RTL 组件测试覆盖渲染/新增/编辑/校验
- paper-form.tsx:JSON textarea 替换为 QuestionList,保存时序列化 QuizQ[]
- vitest.config.ts:加 @vitejs/plugin-react 支持 JSX 组件测试
- test-setup.ts:注册 afterEach cleanup 避免跨测试 DOM 污染

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

package.json

@@ -41,6 +41,7 @@
     "@types/node": "^24.0.0",
     "@types/react": "^19.1.8",
     "@types/react-dom": "^19.1.6",
+    "@vitejs/plugin-react": "^6.1.0",
     "dotenv": "^17.2.0",
     "drizzle-kit": "^0.31.4",
     "jsdom": "^30.0.1",