fix: 更换前端端口 9948 -> 18081 解决 Windows 权限问题

- 前端端口改为 18081
- 添加 host: 127.0.0.1 配置
- 更新 CORS 允许新前端地址
- 更新启动/停止脚本

script/start.bat

@@ -5,7 +5,7 @@ echo.
 
 set "ROOT_PATH=%~dp0.."
 set "BACKEND_PORT=18080"
-set "FRONTEND_PORT=9948"
+set "FRONTEND_PORT=18081"
 
 REM 1. Clean processes on ports
 echo [1/4] Cleaning old processes...
@@ -82,7 +82,7 @@ echo.
 
 echo === All services started ===
 echo Backend: http://127.0.0.1:18080
-echo Frontend: http://localhost:9948
+echo Frontend: http://127.0.0.1:18081
 echo.
 echo Press any key to close this window (services will keep running).
 pause >nul