Temporary setup of alternative to advertisements

lib/screens/confirm_fuel_entry_screen.dart

@@ -127,11 +127,21 @@ class _ConfirmFuelEntryScreenState extends State<ConfirmFuelEntryScreen> {
           );
       if (!mounted) return;
 
+      // The entry is already committed by this point, so the ad isn't
+      // gating the save — it just fills the moment between saving and
+      // landing back on the list. Awaited rather than fired off, so the
+      // two don't race and the ad can't end up drawn over the Receipts
+      // tab after this screen has gone.
+      final adShown = await appState.maybeShowFuelSaveAd();
+      if (!mounted) return;
+
       // Ask while this screen (and its context) is still fully alive,
       // before popping — simpler than trying to show a dialog against a
-      // context whose widget is mid-removal.
+      // context whose widget is mid-removal. Held back when an ad just
+      // ran: one full-screen surface per save, and the reminder comes
+      // back around on the next save anyway.
       var wantsBackupSetup = false;
-      if (!appState.hasCloudBackupConfigured) {
+      if (!adShown && !appState.hasCloudBackupConfigured) {
         wantsBackupSetup = await showBackupReminderDialog(context);
         if (!mounted) return;
       }