feat: add service start/stop scripts for Windows and Linux

停止FTP服务.bat

@@ -0,0 +1,20 @@
+@echo off
+chcp 65001 >nul 2>&1
+title FTP Server - 停止
+
+cd /d "%~dp0"
+
+echo.
+echo   [停止] 正在停止 FTP Server ...
+
+tasklist /FI "IMAGENAME eq ftp-server.exe" 2>nul | find /i "ftp-server.exe" >nul
+if %errorlevel%==0 (
+    taskkill /F /IM "ftp-server.exe" >nul 2>&1
+    timeout /t 1 /nobreak >nul
+    echo   [成功] FTP Server 已停止
+) else (
+    echo   [提示] FTP Server 未在运行
+)
+
+echo.
+pause