fixes before build 3

lib/services/app_settings.dart

@@ -68,6 +68,15 @@ class AppSettings extends ChangeNotifier {
     catalogGeneration++;
     notifyListeners();
   }
+
+  Future<void> wipeAllData() async {
+    await repository.wipeAllData();
+    darkMode = false;
+    supermarkets = List<Supermarket>.from(kDefaultSupermarkets);
+    catalogGeneration++;
+    notifyListeners();
+    await load();
+  }
 }
 
 class SettingsScope extends InheritedNotifier<AppSettings> {

lib/services/product_repository.dart

@@ -1148,6 +1148,7 @@ class ProductRepository extends ChangeNotifier {
     double? price,
     int? quantity,
     double? unitPrice,
+    bool clearQuantity = false,
   }) async {
     final db = await _database;
     final rows = await db.query(
@@ -1161,8 +1162,13 @@ class ProductRepository extends ChangeNotifier {
     final values = <String, Object?>{};
     if (name != null) values['name'] = name.trim();
     if (price != null) values['price'] = price;
-    if (quantity != null) values['quantity'] = quantity;
-    if (unitPrice != null) values['unit_price'] = unitPrice;
+    if (clearQuantity) {
+      values['quantity'] = null;
+      values['unit_price'] = null;
+    } else {
+      if (quantity != null) values['quantity'] = quantity;
+      if (unitPrice != null) values['unit_price'] = unitPrice;
+    }
     if (values.isEmpty) return;
     await db.update('shop_items', values, where: 'id = ?', whereArgs: [id]);
     await _recalculateShopTotal(shopId);
@@ -1540,15 +1546,45 @@ class ProductRepository extends ChangeNotifier {
   }
 
   Future<void> clearImageFolders() async {
-    final dir = await getApplicationDocumentsDirectory();
-    for (final name in ['receipts', 'products']) {
-      final folder = Directory(p.join(dir.path, name));
-      if (await folder.exists()) {
-        await folder.delete(recursive: true);
+    try {
+      final dir = await getApplicationDocumentsDirectory();
+      for (final name in ['receipts', 'products', 'bonus_cards']) {
+        final folder = Directory(p.join(dir.path, name));
+        if (await folder.exists()) {
+          await folder.delete(recursive: true);
+        }
       }
+    } catch (_) {
+      // Platform folders are unavailable in some unit tests.
     }
   }
 
+  /// Deletes all app data and restores default supermarkets.
+  Future<void> wipeAllData() async {
+    final db = await _database;
+    await db.transaction((txn) async {
+      await txn.delete('shopping_list_items');
+      await txn.delete('shopping_lists');
+      await txn.delete('shop_tags');
+      await txn.delete('shop_items');
+      await txn.delete('shops');
+      await txn.delete('products');
+      await txn.delete('supermarkets');
+      await txn.delete('app_settings');
+
+      await _resetSequence(txn, 'supermarkets');
+      await _resetSequence(txn, 'products');
+      await _resetSequence(txn, 'shops');
+      await _resetSequence(txn, 'shop_items');
+      await _resetSequence(txn, 'shop_tags');
+      await _resetSequence(txn, 'shopping_lists');
+      await _resetSequence(txn, 'shopping_list_items');
+      await _seedSupermarkets(txn);
+    });
+    await clearImageFolders();
+    notifyListeners();
+  }
+
   Future<void> replaceAllData({
     required List<Map<String, Object?>> supermarkets,
     required List<Map<String, Object?>> products,