feat: 新增客户端错误收集与admin监控接口

- POST /api/client-errors: 批量存储客户端错误（10分钟去重合并）
- GET /api/client-errors: admin分页查看错误列表
- DELETE /api/client-errors: admin清空错误记录
- 72小时自动清理旧数据

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/routes/index.js

@@ -17,7 +17,8 @@ const { registerConversationRoutes } = require('./conversations')
 const { registerReportRoutes } = require('./reports')
 const { registerAssetRoutes } = require('./assets')
 const { registerNotificationRoutes } = require('./notifications')
-const { registerDraftRoutes } = require('./drafts')
+const { registerDraftRoutes } = require('./drafts');
+const mountClientErrorRoutes = require('./clientErrors')
 
 const router = express.Router()