Refactor category handling in inventory and pantry forms

- Introduced `_categorySearchController` and `_categoryOptions` in both `_InventoryFormDialogState` and `_PantryFormDialogState` to manage category selection more effectively.
- Implemented `_flattenCategoryOptions` method to create a flat list of category options from nested category nodes.
- Updated the initialization and disposal of the new controllers to ensure proper resource management.
- Made minor adjustments to the PopupMenuItem definitions in `AppShell` for consistency.

flutter/build/web/flutter_bootstrap.js

@@ -37,6 +37,6 @@ _flutter.buildConfig = {"engineRevision":"59aa584fdf100e6c78c785d8a5b565d1de4b48
 
 _flutter.loader.load({
   serviceWorkerSettings: {
-    serviceWorkerVersion: "3795187910" /* Flutter's service worker is deprecated and will be removed in a future Flutter release. */
+    serviceWorkerVersion: "2742817442" /* Flutter's service worker is deprecated and will be removed in a future Flutter release. */
   }
 });

flutter/lib/core/ui/app_shell.dart

@@ -210,8 +210,8 @@ class AppShell extends ConsumerWidget {
                   break;
               }
             },
-            itemBuilder: (context) => const [
+            itemBuilder: (context) => [
-              PopupMenuItem<String>(
+              const PopupMenuItem<String>(
                 value: 'profile',
                 child: ListTile(
                   leading: Icon(Icons.person_outline),
@@ -220,7 +220,7 @@ class AppShell extends ConsumerWidget {
                 ),
               ),
               if (isAdmin)
-                PopupMenuItem<String>(
+                const PopupMenuItem<String>(
                   value: 'admin',
                   child: ListTile(
                     leading: Icon(Icons.admin_panel_settings_outlined),
@@ -228,8 +228,8 @@ class AppShell extends ConsumerWidget {
                     contentPadding: EdgeInsets.zero,
                   ),
                 ),
-              PopupMenuDivider(),
+              const PopupMenuDivider(),
-              PopupMenuItem<String>(
+              const PopupMenuItem<String>(
                 value: 'logout',
                 child: ListTile(
                   leading: Icon(Icons.logout),

flutter/lib/features/admin/presentation/admin_inventory_panel.dart

@@ -781,6 +781,8 @@ class _InventoryFormDialogState extends State<_InventoryFormDialog> {
   late final TextEditingController _receiptNameController;
   late final TextEditingController _suitableForController;
   late final TextEditingController _commentController;
+  late final TextEditingController _categorySearchController;
+  late List<CategorySelectOption> _categoryOptions;
 
   int? _ownerUserId;
   int? _productId;
@@ -806,6 +808,8 @@ class _InventoryFormDialogState extends State<_InventoryFormDialog> {
     _receiptNameController = TextEditingController(text: initial?.receiptName ?? '');
     _suitableForController = TextEditingController(text: initial?.suitableFor ?? '');
     _commentController = TextEditingController(text: initial?.comment ?? '');
+    _categorySearchController = TextEditingController(text: _categoryPath ?? '');
+    _categoryOptions = _flattenCategoryOptions(widget.categories);
   }
 
   @override
@@ -817,6 +821,7 @@ class _InventoryFormDialogState extends State<_InventoryFormDialog> {
     _receiptNameController.dispose();
     _suitableForController.dispose();
     _commentController.dispose();
+    _categorySearchController.dispose();
     super.dispose();
   }
 
@@ -853,6 +858,20 @@ class _InventoryFormDialogState extends State<_InventoryFormDialog> {
         .toList();
   }
 
+  List<CategorySelectOption> _flattenCategoryOptions(
+    List<AdminCategoryNode> nodes, [
+    List<String> parents = const [],
+  ]) {
+    final result = <CategorySelectOption>[];
+    for (final node in nodes) {
+      final pathParts = [...parents, node.name];
+      final path = pathParts.join(' > ');
+      result.add((value: node.id.toString(), label: path));
+      result.addAll(_flattenCategoryOptions(node.children, pathParts));
+    }
+    return result;
+  }
+
   Future<void> _pickCategory() async {
     final selected = await CategoryThenProductPicker.showCategorySheet(
       context,

flutter/lib/features/admin/presentation/admin_pantry_panel.dart

@@ -506,6 +506,9 @@ class _PantryFormDialog extends StatefulWidget {
 
 class _PantryFormDialogState extends State<_PantryFormDialog> {
   late final TextEditingController _locationController;
+  late final TextEditingController _categorySearchController;
+  late List<CategorySelectOption> _categoryOptions;
+  
   int? _ownerUserId;
   int? _productId;
   int? _categoryId;
@@ -522,11 +525,14 @@ class _PantryFormDialogState extends State<_PantryFormDialog> {
     _categoryId = initialProduct?.categoryId;
     _categoryPath = initialProduct?.categoryPath;
     _locationController = TextEditingController(text: initial?.location ?? '');
+    _categorySearchController = TextEditingController(text: _categoryPath ?? '');
+    _categoryOptions = _flattenCategoryOptions(widget.categories);
   }
 
   @override
   void dispose() {
     _locationController.dispose();
+    _categorySearchController.dispose();
     super.dispose();
   }
 
@@ -563,6 +569,20 @@ class _PantryFormDialogState extends State<_PantryFormDialog> {
         .toList();
   }
 
+  List<CategorySelectOption> _flattenCategoryOptions(
+    List<AdminCategoryNode> nodes, [
+    List<String> parents = const [],
+  ]) {
+    final result = <CategorySelectOption>[];
+    for (final node in nodes) {
+      final pathParts = [...parents, node.name];
+      final path = pathParts.join(' > ');
+      result.add((value: node.id.toString(), label: path));
+      result.addAll(_flattenCategoryOptions(node.children, pathParts));
+    }
+    return result;
+  }
+
   Future<void> _pickCategory() async {
     final selected = await CategoryThenProductPicker.showCategorySheet(
       context,