Adopt OCSentinel script layout and add Gitea workflow

installer/uninstall-ocsentinel.ps1

@@ -0,0 +1,16 @@
+param()
+
+$ErrorActionPreference = "Stop"
+
+$installRoot = Join-Path ${env:ProgramFiles} "OCSentinel"
+$uninstallKey = "HKLM:\Software\Microsoft\Windows\CurrentVersion\Uninstall\OCSentinel"
+
+if (Test-Path $uninstallKey) {
+    Remove-Item -Path $uninstallKey -Force -Recurse
+}
+
+if (Test-Path $installRoot) {
+    Remove-Item -LiteralPath $installRoot -Force -Recurse
+}
+
+Write-Host "OfficeCom Sentinel removed from $installRoot"