fix(agent): normalize Windows updater paths

update_gewu.bat

@@ -2,6 +2,7 @@
 setlocal
 
 set "PACK=%~dp0"
+if "%PACK:~-1%"=="\" set "PACK=%PACK:~0,-1%"
 if "%~1"=="" (
     for %%I in ("%PACK%..") do set "WORKSPACE=%%~fI"
 ) else (
@@ -14,7 +15,7 @@ git -C "%PACK%" pull --ff-only
 if errorlevel 1 goto :pull_failed
 
 echo [2/3] Verifying the pulled pack...
-python "%PACK%scripts\manifest_tool.py" verify
+python "%PACK%\scripts\manifest_tool.py" verify
 if errorlevel 1 goto :source_verify_failed
 
 if not exist "%DEST%\" (