Added onboarding + a lightweight install banner to both the mobile login screen and the settings screen, with Android/Chromium

install prompt support and iOS “Share → Add to Home Screen” guidance. Also added a small helper + tests to decide
  when/which banner variant should show, and shared copy in common.json.

resources/js/admin/mobile/lib/mobileTour.ts

@@ -0,0 +1,9 @@
+export type TourStepKey = 'event' | 'qr' | 'photos' | 'push';
+
+export function resolveTourStepKeys(hasEvents: boolean): TourStepKey[] {
+  if (hasEvents) {
+    return ['qr', 'photos', 'push'];
+  }
+
+  return ['event', 'qr', 'photos', 'push'];
+}