Ship uninstaller in agent bundle and harden tray launch

The site-agent bundle now includes uninstall-shopdbagent.ps1 so operators can cleanly remove an install without hunting for the repo script. The packaging route reads it from scripts/, which was not mounted into the api container, so add a read-only ./scripts:/app/scripts mount (recreate the container to apply).

install.ps1 now registers the tray to autostart for every user via the HKLM Run value ShopDbEndpointTray, adds an All-Users 'ShopDB Agent' Start Menu shortcut for manual relaunch, and launches the tray once post-install. The tray enforces a single instance via a Global named mutex so repeated launches no longer stack duplicate icons. The uninstaller removes the Start Menu shortcut alongside the existing Run key and credential cleanup.

scripts/uninstall-shopdbagent.ps1

@@ -114,6 +114,14 @@ Start-Sleep -Seconds 1
 Write-Host "[3/6] Removing registry entries ..."
 Remove-HklmBothViews -SubKey "SOFTWARE\Microsoft\Windows\CurrentVersion\Run" -Name "ShopDbEndpointTray"
 Remove-HklmBothViews -SubKey "SOFTWARE\GE\ShopDB"
+
+# Remove the All-Users Start Menu shortcut the site-agent installer created.
+$commonPrograms = [Environment]::GetFolderPath([Environment+SpecialFolder]::CommonPrograms)
+$shortcutPath = Join-Path $commonPrograms "ShopDB Agent.lnk"
+if (Test-Path $shortcutPath) {
+	try { Remove-Item -Path $shortcutPath -Force -ErrorAction Stop; Write-Host "  removed Start Menu shortcut $shortcutPath" }
+	catch { Write-Warning "  could not remove Start Menu shortcut: $($_.Exception.Message)" }
+}
 # Drop the parent GE key only if we emptied it (some sites nest siblings under
 # GE such as SFLD; never tree-delete a key we do not own).
 foreach ($view in @([Microsoft.Win32.RegistryView]::Registry64,