Offline queue: retry kirim setelah refresh/poll sukses + verifikasi server reachable + log gagal sinkron + izin INTERNET/ACCESS_NETWORK_STATE Android

lib/state/app_state.dart

@@ -224,6 +224,8 @@ class AppState extends ChangeNotifier {
       await _loadProducts();
       await _loadSales();
       dataReady = true;
+      // Server terbukti reachable → coba kirim antrean transaksi offline.
+      await _offlineQueue.retryNow();
     } catch (e) {
       productsError ??= e.toString();
       if (retries > 0) {