chore(import): improve error handling and add flyer integration

- Replace BadRequestException with UnauthorizedException for authentication failures in flyer-import and flyer-selection controllers
- Add bulk selection endpoint in FlyerSelectionController for creating multiple selections in one request
- Update FlyerSelectionModule to include new FlyerSelectionMatcherService and FlyerSelectionSyncController
- Extend FlyerSelectionService with createMany method for bulk operations
- Add new DTOs for bulk selection and receipt matching functionality
- Update ReceiptImportService to accept FlyerSelectionService dependency and track successful rows
- Extend SaveReceiptResponse with flyerAutoSync field for receipt-to-flyer matching results
- Add new API paths for flyer import and selection endpoints
- Update Flutter UI to include Flyer import tab and adjust tab controller length
- Add new domain models and repository methods for flyer import functionality
- Update test files to include new FlyerSelectionService dependency
- Modify .kilo plan documentation to reflect current system architecture

flutter/lib/features/import/domain/flyer_import_item.dart

@@ -0,0 +1,43 @@
+class FlyerImportItem {
+  final int? flyerItemId;
+  final String rawName;
+  final String normalizedName;
+  final String? category;
+  final double? price;
+  final String? priceUnit;
+  final String? offerText;
+  final int? matchedProductId;
+  final String? matchedProductName;
+  final String? matchedVia;
+  final double? matchConfidence;
+
+  FlyerImportItem({
+    required this.flyerItemId,
+    required this.rawName,
+    required this.normalizedName,
+    this.category,
+    this.price,
+    this.priceUnit,
+    this.offerText,
+    this.matchedProductId,
+    this.matchedProductName,
+    this.matchedVia,
+    this.matchConfidence,
+  });
+
+  factory FlyerImportItem.fromJson(Map<String, dynamic> json) {
+    return FlyerImportItem(
+      flyerItemId: (json['flyerItemId'] as num?)?.toInt(),
+      rawName: json['rawName'] as String? ?? '',
+      normalizedName: json['normalizedName'] as String? ?? '',
+      category: json['category'] as String?,
+      price: (json['price'] as num?)?.toDouble(),
+      priceUnit: json['priceUnit'] as String?,
+      offerText: json['offerText'] as String?,
+      matchedProductId: (json['matchedProductId'] as num?)?.toInt(),
+      matchedProductName: json['matchedProductName'] as String?,
+      matchedVia: json['matchedVia'] as String?,
+      matchConfidence: (json['matchConfidence'] as num?)?.toDouble(),
+    );
+  }
+}

flutter/lib/features/import/domain/flyer_import_result.dart

@@ -0,0 +1,29 @@
+import 'flyer_import_item.dart';
+
+class FlyerImportResult {
+  final int? sessionId;
+  final List<FlyerImportItem> items;
+  final List<String> warnings;
+
+  FlyerImportResult({
+    required this.sessionId,
+    required this.items,
+    required this.warnings,
+  });
+
+  factory FlyerImportResult.fromJson(Map<String, dynamic> json) {
+    final rawItems = (json['items'] as List?) ?? const [];
+    final warnings = (json['warnings'] as List?)
+            ?.map((warning) => warning.toString())
+            .toList() ??
+        const <String>[];
+
+    return FlyerImportResult(
+      sessionId: (json['sessionId'] as num?)?.toInt(),
+      items: rawItems
+          .map((item) => FlyerImportItem.fromJson(item as Map<String, dynamic>))
+          .toList(),
+      warnings: warnings,
+    );
+  }
+}