true on iOS Safari when the app is NOT already installed — i.e. the user can still
add it to the home screen. iOS never fires beforeinstallprompt, so this UA +
navigator.standalone check is the only "installable" signal available on that
platform (used by PWAManager.isInstallable() and the iOS instructions banner).
trueon iOS Safari when the app is NOT already installed — i.e. the user can still add it to the home screen. iOS never firesbeforeinstallprompt, so this UA +navigator.standalonecheck is the only "installable" signal available on that platform (used byPWAManager.isInstallable()and the iOS instructions banner).