feat(task1): restructure directories for turborepo monorepo

- Move backend/ to apps/server/ via git mv
- Move frontend/ to apps/admin/ via git mv
- Create packages/typescript-config/ with base, nestjs, and react-vite presets

apps/server/src/common/request-utils.ts

@@ -0,0 +1,9 @@
+/**
+ * 从请求对象中提取客户端 IP 和 UserAgent
+ */
+export function extractRequestInfo(req: any): { ipAddress: string; userAgent: string } {
+  const forwarded = req.headers?.['x-forwarded-for'] || req.headers?.['x-real-ip'] || req.connection?.remoteAddress || '';
+  const ipAddress = String(forwarded).split(',')[0].trim() || 'unknown';
+  const userAgent = (req.headers?.['user-agent'] || '').substring(0, 500);
+  return { ipAddress, userAgent };
+}