fix: ethend.bat 端口检测改用变量避免for循环内交互闪退

ethend.bat

@@ -126,17 +126,19 @@ if %ERRORLEVEL%==0 (
     exit /b 0
 )
 
-:: Check port conflict and ask user
-for /f "tokens=5" %%a in ('netstat -ano ^| findstr /R ":%ETHEND_PORT% " ^| findstr "LISTENING"') do (
+:: Check port conflict
+set FOUND_PID=
+for /f "tokens=5" %%a in ('netstat -ano ^| findstr /R ":%ETHEND_PORT% " ^| findstr "LISTENING"') do set FOUND_PID=%%a
+if not "%FOUND_PID%"=="" (
     echo.
-    echo [WARN] Port %ETHEND_PORT% is in use by PID %%a.
+    echo [WARN] Port %ETHEND_PORT% is in use by PID %FOUND_PID%.
     set /p CHOICE="Kill old process and restart? [Y/n]: "
     if /i "!CHOICE!"=="n" (
         echo [INFO] Aborted by user.
         exit /b 0
     )
-    echo [INFO] Killing PID %%a...
-    taskkill /PID %%a /F >nul 2>&1
+    echo [INFO] Killing PID %FOUND_PID%...
+    taskkill /PID %FOUND_PID% /F >nul 2>&1
     timeout /t 2 /nobreak >nul
 )