feat(inventory): implement swipeable inventory tile and product picker field

flutter/lib/features/pantry/presentation/pantry_screen.dart

@@ -3,6 +3,7 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 
 import '../../../core/api/api_error_mapper.dart';
 import '../../../core/forms/form_options.dart';
+import '../../../core/ui/product_picker_field.dart';
 import '../../../features/inventory/data/inventory_providers.dart';
 import '../../auth/data/auth_providers.dart';
 import '../../../core/ui/async_state_views.dart';
@@ -264,6 +265,9 @@ class _PantryScreenState extends ConsumerState<PantryScreen> {
         (a, b) =>
             a.displayName.toLowerCase().compareTo(b.displayName.toLowerCase()),
       );
+    final availableOptions = availableProducts
+        .map((p) => (id: p.id, name: p.displayName))
+        .toList();
 
     final grouped = <String, List<PantryItem>>{};
     for (final item in pantryItems) {
@@ -289,27 +293,12 @@ class _PantryScreenState extends ConsumerState<PantryScreen> {
           crossAxisAlignment: CrossAxisAlignment.start,
           children: [
             Expanded(
-              child: DropdownButtonFormField<int>(
+              child: ProductPickerField(
+                products: availableOptions,
                 value: _selectedProductId,
-                isExpanded: true,
-                decoration: const InputDecoration(
-                  labelText: 'Produkt',
-                  border: OutlineInputBorder(),
-                ),
-                items: availableProducts
-                    .map(
-                      (product) => DropdownMenuItem<int>(
-                        value: product.id,
-                        child: Text(
-                          product.displayName,
-                          overflow: TextOverflow.ellipsis,
-                        ),
-                      ),
-                    )
-                    .toList(),
-                onChanged: _isSubmitting
-                    ? null
-                    : (value) => setState(() => _selectedProductId = value),
+                enabled: !_isSubmitting && availableProducts.isNotEmpty,
+                label: 'Produkt',
+                onChanged: (value) => setState(() => _selectedProductId = value),
               ),
             ),
             const SizedBox(width: 8),