feat: enhance inventory and pantry features with filtering, sorting, and error handling improvements

flutter/lib/features/pantry/domain/pantry_product.dart

@@ -3,12 +3,16 @@ class PantryProduct {
   final String name;
   final String? canonicalName;
   final String? category;
+  final int? categoryId;
+  final String? categoryPath;
 
   const PantryProduct({
     required this.id,
     required this.name,
     this.canonicalName,
     this.category,
+    this.categoryId,
+    this.categoryPath,
   });
 
   String get displayName {
@@ -19,11 +23,33 @@ class PantryProduct {
   }
 
   factory PantryProduct.fromJson(Map<String, dynamic> json) {
+    final categoryRef = json['categoryRef'];
+    final path = _buildCategoryPath(categoryRef);
+
     return PantryProduct(
       id: (json['id'] as num).toInt(),
       name: (json['name'] ?? '').toString(),
       canonicalName: json['canonicalName']?.toString(),
       category: json['category']?.toString(),
+      categoryId: (json['categoryId'] as num?)?.toInt(),
+      categoryPath: path,
     );
   }
+
+  static String? _buildCategoryPath(dynamic rawCategoryRef) {
+    if (rawCategoryRef is! Map<String, dynamic>) return null;
+
+    final names = <String>[];
+    dynamic current = rawCategoryRef;
+    while (current is Map<String, dynamic>) {
+      final name = current['name']?.toString().trim();
+      if (name != null && name.isNotEmpty) {
+        names.insert(0, name);
+      }
+      current = current['parent'];
+    }
+
+    if (names.isEmpty) return null;
+    return names.join(' > ');
+  }
 }