parser logic added

lib/home_shell.dart

@@ -1,4 +1,4 @@
-/// Bottom navigation: products, scan, and shop log.
+/// Bottom navigation: products, lists, add, and shop log.
 library;
 
 import 'package:flutter/material.dart';
@@ -8,6 +8,7 @@ import 'scan_screen.dart';
 import 'services/app_settings.dart';
 import 'services/product_repository.dart';
 import 'shop_log_screen.dart';
+import 'shopping_lists_screen.dart';
 
 class HomeShell extends StatefulWidget {
   const HomeShell({super.key, required this.repository});
@@ -19,10 +20,10 @@ class HomeShell extends StatefulWidget {
 }
 
 class _HomeShellState extends State<HomeShell> {
-  static const _scanIndex = 1;
-  static const _shopLogIndex = 2;
+  static const _addIndex = 2;
+  static const _shopLogIndex = 3;
 
-  int _index = _scanIndex;
+  int _index = _addIndex;
   int _revision = 0;
   AppSettings? _settings;
   int _seenGeneration = 0;
@@ -59,9 +60,8 @@ class _HomeShellState extends State<HomeShell> {
     });
     WidgetsBinding.instance.addPostFrameCallback((_) {
       if (!mounted) return;
-      ScaffoldMessenger.of(context).showSnackBar(
-        const SnackBar(content: Text('Shopping trip saved.')),
-      );
+      ScaffoldMessenger.of(context)
+          .showSnackBar(const SnackBar(content: Text('Shopping trip saved.')));
     });
   }
 
@@ -70,17 +70,21 @@ class _HomeShellState extends State<HomeShell> {
     return Scaffold(
       body: switch (_index) {
         0 => ProductsScreen(
-            key: ValueKey('products-$_revision'),
-            repository: widget.repository,
-          ),
-        1 => ScanScreen(
-            repository: widget.repository,
-            onTripSaved: _onTripSaved,
-          ),
+          key: ValueKey('products-$_revision'),
+          repository: widget.repository,
+        ),
+        1 => ShoppingListsScreen(
+          key: ValueKey('lists-$_revision'),
+          repository: widget.repository,
+        ),
+        2 => ScanScreen(
+          repository: widget.repository,
+          onTripSaved: _onTripSaved,
+        ),
         _ => ShopLogScreen(
-            key: ValueKey('shops-$_revision'),
-            repository: widget.repository,
-          ),
+          key: ValueKey('shops-$_revision'),
+          repository: widget.repository,
+        ),
       },
       bottomNavigationBar: NavigationBar(
         selectedIndex: _index,
@@ -92,9 +96,14 @@ class _HomeShellState extends State<HomeShell> {
             label: 'Products',
           ),
           NavigationDestination(
-            icon: Icon(Icons.photo_camera_outlined),
-            selectedIcon: Icon(Icons.photo_camera),
-            label: 'Scan',
+            icon: Icon(Icons.checklist_outlined),
+            selectedIcon: Icon(Icons.checklist),
+            label: 'Lists',
+          ),
+          NavigationDestination(
+            icon: Icon(Icons.add),
+            selectedIcon: Icon(Icons.add_circle),
+            label: 'Add',
           ),
           NavigationDestination(
             icon: Icon(Icons.receipt_long_outlined),