Enforce a single running instance and add the app icon - A second GUI launch now detects the running host via a named mutex, asks it to open the settings window over IPC, and exits. - New delta app icon (Assets/app.ico, 7 sizes from icon.png): embedded in the exe, used by the tray icon, and passed to vpk pack so the installer and Start Menu shortcut use it too. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>