added product import and billing integration

lib/presentation/modules/screens/events_view.dart

@@ -1,10 +1,12 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 
+import '../../../app/providers.dart';
 import '../../../core/theme/app_colors.dart';
 import '../../../core/theme/app_dimens.dart';
 import '../../../core/utils/formatters.dart';
 import '../../../core/widgets/primary_button.dart';
+import '../../../data/sync/sync_engine.dart';
 import '../../../domain/entities/transaction.dart';
 import '../../../domain/repositories/sync_repository.dart';
 import '../../sync/providers/sync_controller.dart';
@@ -26,10 +28,21 @@ class EventsView extends ConsumerWidget {
     final syncState = ref.watch(orderSyncProvider);
     final events = ref.watch(syncEventsProvider);
 
+    // The engine may not have emitted yet on a cold start, so fall back to
+    // its current value rather than showing nothing. This is the same state
+    // that drives the header pill — it is what actually knows whether the
+    // automatic push right after a sale succeeded, not just what the manual
+    // "Sync" button on this page last did.
+    final engine = ref.watch(syncEngineStateProvider).value ??
+        ref.watch(syncEngineProvider).state;
+
     final r = report.value;
 
     return ModulePage(
       children: [
+        if (engine.lastError != null && pending > 0)
+          _EngineWarningBanner(engine: engine),
+
         Wrap(
           spacing: AppSpacing.lg,
           runSpacing: AppSpacing.lg,
@@ -310,3 +323,81 @@ class EventsView extends ConsumerWidget {
         ),
       );
 }
+
+/// Flags a bill that could not reach the server on its own — the automatic
+/// push right after checkout, not the manual "Sync" button below.
+///
+/// Sits above everything else on the page because a bill stuck here is the
+/// one thing on this screen that needs a person to notice it, rather than
+/// just waiting for the next background retry.
+class _EngineWarningBanner extends StatelessWidget {
+  const _EngineWarningBanner({required this.engine});
+
+  final SyncEngineState engine;
+
+  @override
+  Widget build(BuildContext context) {
+    final halted = engine.isHalted;
+    final color = halted ? AppColors.danger : AppColors.warning;
+    final surface = halted ? AppColors.dangerSurface : AppColors.warningSurface;
+
+    final retry = engine.nextAttemptAt;
+    final retryNote = halted
+        ? 'Retrying will not help until this is fixed — press Sync below '
+            'once it is sorted.'
+        : retry == null
+            ? 'It will retry automatically, or press Sync below to try now.'
+            : 'It will retry automatically at ${Formatters.time(retry)}, or '
+                'press Sync below to try now.';
+
+    return Container(
+      margin: const EdgeInsets.only(bottom: AppSpacing.lg),
+      padding: const EdgeInsets.all(AppSpacing.md),
+      decoration: BoxDecoration(color: surface, borderRadius: AppRadius.brLg),
+      child: Row(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Icon(Icons.wifi_off_rounded, size: 20, color: color),
+          const SizedBox(width: AppSpacing.md),
+          Expanded(
+            child: Column(
+              crossAxisAlignment: CrossAxisAlignment.start,
+              children: [
+                Text(
+                  halted
+                      ? 'Sync halted — ${engine.pending} bill(s) not sent'
+                      : "Couldn't reach the server — "
+                          '${engine.pending} bill(s) not sent',
+                  style: TextStyle(
+                    fontSize: 14,
+                    fontWeight: FontWeight.w700,
+                    color: color,
+                  ),
+                ),
+                const SizedBox(height: 2),
+                Text(
+                  engine.lastError ?? 'The last upload attempt failed.',
+                  style: TextStyle(
+                    fontSize: 12.5,
+                    color: color,
+                    height: 1.45,
+                  ),
+                ),
+                const SizedBox(height: 4),
+                Text(
+                  '$retryNote Every bill is still safe on this terminal — '
+                  'nothing is lost while it waits.',
+                  style: const TextStyle(
+                    fontSize: 12,
+                    color: AppColors.textSecondary,
+                    height: 1.45,
+                  ),
+                ),
+              ],
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}