added installer

Installer/update.bat

@@ -0,0 +1,36 @@
+@echo off
+REM GSP Windows Agent Update Script
+REM This script updates an existing Git-managed agent installation
+
+setlocal enabledelayedexpansion
+
+REM Check for Administrator privileges
+net session >nul 2>&1
+if %errorlevel% neq 0 (
+    echo.
+    echo ERROR: This updater must be run as Administrator.
+    echo.
+    echo Please:
+    echo  1. Right-click this batch file
+    echo  2. Select "Run as Administrator"
+    echo  3. Click "Yes" when prompted
+    echo.
+    pause
+    exit /b 1
+)
+
+REM Get the directory where this batch file is located
+set "SCRIPT_DIR=%~dp0"
+
+REM Verify the PowerShell script exists
+if not exist "%SCRIPT_DIR%Update-GSP-WindowsAgent.ps1" (
+    echo ERROR: Update-GSP-WindowsAgent.ps1 not found in %SCRIPT_DIR%
+    pause
+    exit /b 1
+)
+
+REM Launch the PowerShell updater
+powershell.exe -NoProfile -ExecutionPolicy Bypass -Command "& '%SCRIPT_DIR%Update-GSP-WindowsAgent.ps1'" %*
+
+REM Exit with PowerShell's exit code
+exit /b %ERRORLEVEL%