Add accsaber and don't update menu after reloading

menu.bat

@@ -3,23 +3,36 @@ setlocal
 
 cd /d "%~dp0"
 
-if not exist ".venv\Scripts\python.exe" (
+set "VENV_PY=.venv\Scripts\python.exe"
+set "STAMP_FILE=.venv\.last-install"
+set "NEED_INSTALL=0"
+
+if not exist "%VENV_PY%" (
     echo Creating virtual environment...
     py -m venv .venv
     if errorlevel 1 (
         echo Failed to create virtual environment.
         exit /b 1
     )
+    set "NEED_INSTALL=1"
+) else if not exist "%STAMP_FILE%" (
+    set "NEED_INSTALL=1"
+) else (
+    "%VENV_PY%" -c "import pathlib, sys, time; p=pathlib.Path(r'%STAMP_FILE%'); sys.exit(0 if time.time()-p.stat().st_mtime >= 20*3600 else 1)"
+    if not errorlevel 1 set "NEED_INSTALL=1"
 )
 
-echo Installing plugin-helper...
-".venv\Scripts\python.exe" -m pip install -e .
-if errorlevel 1 (
-    echo Failed to install plugin-helper.
-    exit /b 1
+if "%NEED_INSTALL%"=="1" (
+    echo Installing plugin-helper...
+    "%VENV_PY%" -m pip install -e .
+    if errorlevel 1 (
+        echo Failed to install plugin-helper.
+        exit /b 1
+    )
+    type nul > "%STAMP_FILE%"
 )
 
-".venv\Scripts\python.exe" -m plugin_helper
+"%VENV_PY%" -m plugin_helper
 set EXIT_CODE=%ERRORLEVEL%
 
 endlocal & exit /b %EXIT_CODE%