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

flutter/lib/features/inventory/presentation/consumption_history_screen.dart

@@ -1,6 +1,7 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 
+import '../../../core/api/api_error_mapper.dart';
 import '../../../core/ui/async_state_views.dart';
 import '../data/inventory_providers.dart';
 import '../domain/inventory_consumption.dart';
@@ -25,7 +26,7 @@ class ConsumptionHistoryScreen extends ConsumerWidget {
       body: historyAsync.when(
         loading: () => const LoadingStateView(label: 'Laddar historik...'),
         error: (e, _) => ErrorStateView(
-          message: e.toString(),
+          message: mapErrorToUserMessage(e),
           onRetry: () => ref.invalidate(consumptionHistoryProvider(itemId)),
         ),
         data: (history) {

flutter/lib/features/inventory/presentation/inventory_detail_screen.dart

@@ -36,7 +36,7 @@ class InventoryDetailScreen extends ConsumerWidget {
       body: itemAsync.when(
         loading: () => const LoadingStateView(label: 'Laddar...'),
         error: (e, _) => ErrorStateView(
-          message: e.toString(),
+          message: mapErrorToUserMessage(e),
           onRetry: () => ref.invalidate(inventoryDetailProvider(itemId)),
         ),
         data: (item) => ListView(

flutter/lib/features/inventory/presentation/inventory_edit_screen.dart

@@ -130,7 +130,7 @@ class _InventoryEditScreenState extends ConsumerState<InventoryEditScreen> {
       body: itemAsync.when(
         loading: () => const LoadingStateView(label: 'Laddar...'),
         error: (e, _) => ErrorStateView(
-          message: e.toString(),
+          message: mapErrorToUserMessage(e),
           onRetry: () => ref.invalidate(inventoryDetailProvider(widget.itemId)),
         ),
         data: (item) {

flutter/lib/features/inventory/presentation/inventory_screen.dart

@@ -11,21 +11,87 @@ import '../domain/inventory_item.dart';
 class InventoryScreen extends ConsumerWidget {
   const InventoryScreen({super.key});
 
+  static const _locationOptions = <String>['', 'Kyl', 'Frys', 'Skafferi'];
+  static const _sortOptions = <({String value, String label})>[
+    (value: '', label: 'Senast tillagda'),
+    (value: 'nameAsc', label: 'Namn A-O'),
+    (value: 'bestBeforeAsc', label: 'Bast fore stigande'),
+    (value: 'bestBeforeDesc', label: 'Bast fore fallande'),
+  ];
+
   @override
   Widget build(BuildContext context, WidgetRef ref) {
+    final location = ref.watch(inventoryLocationFilterProvider);
+    final sort = ref.watch(inventorySortFilterProvider);
     final inventoryAsync = ref.watch(inventoryProvider);
 
     return inventoryAsync.when(
       loading: () => const LoadingStateView(label: 'Laddar inventarie...'),
       error: (e, _) => ErrorStateView(
-        message: e.toString(),
+        message: mapErrorToUserMessage(e),
         onRetry: () => ref.invalidate(inventoryProvider),
       ),
       data: (items) {
+        final filterSection = Padding(
+          padding: const EdgeInsets.fromLTRB(12, 12, 12, 4),
+          child: Column(
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: [
+              const Text(
+                'Filter och sortering',
+                style: TextStyle(fontWeight: FontWeight.w600),
+              ),
+              const SizedBox(height: 8),
+              Wrap(
+                spacing: 8,
+                runSpacing: 8,
+                children: _locationOptions
+                    .map(
+                      (option) => ChoiceChip(
+                        label: Text(option.isEmpty ? 'Alla' : option),
+                        selected: location == option,
+                        onSelected: (_) => ref
+                            .read(inventoryLocationFilterProvider.notifier)
+                            .state = option,
+                      ),
+                    )
+                    .toList(),
+              ),
+              const SizedBox(height: 8),
+              DropdownButtonFormField<String>(
+                value: sort,
+                isExpanded: true,
+                decoration: const InputDecoration(
+                  labelText: 'Sortering',
+                  border: OutlineInputBorder(),
+                ),
+                items: _sortOptions
+                    .map(
+                      (option) => DropdownMenuItem<String>(
+                        value: option.value,
+                        child: Text(option.label),
+                      ),
+                    )
+                    .toList(),
+                onChanged: (value) {
+                  ref.read(inventorySortFilterProvider.notifier).state =
+                      value ?? '';
+                },
+              ),
+            ],
+          ),
+        );
+
         if (items.isEmpty) {
           return Stack(
             children: [
-              const EmptyStateView(title: 'Inventariet är tomt.'),
+              ListView(
+                padding: const EdgeInsets.only(bottom: 88),
+                children: [
+                  filterSection,
+                  const EmptyStateView(title: 'Inventariet ar tomt.'),
+                ],
+              ),
               Positioned(
                 right: 16,
                 bottom: 16,
@@ -42,10 +108,11 @@ class InventoryScreen extends ConsumerWidget {
           children: [
             ListView.separated(
               padding: const EdgeInsets.only(bottom: 88),
-              itemCount: items.length,
+              itemCount: items.length + 1,
               separatorBuilder: (_, __) => const Divider(height: 1),
               itemBuilder: (context, index) {
-                final item = items[index];
+                if (index == 0) return filterSection;
+                final item = items[index - 1];
                 return _InventoryTile(item: item);
               },
             ),