major refactor

lib/components/pages/new_entry.dart

@@ -8,8 +8,8 @@ import 'package:intl/intl.dart';
 import 'package:mileograph_flutter/components/calculator/calculator.dart';
 import 'package:mileograph_flutter/components/pages/traction.dart';
 import 'package:mileograph_flutter/objects/objects.dart';
-import 'package:mileograph_flutter/services/apiService.dart';
-import 'package:mileograph_flutter/services/dataService.dart';
+import 'package:mileograph_flutter/services/api_service.dart';
+import 'package:mileograph_flutter/services/data_service.dart';
 import 'package:mileograph_flutter/services/navigation_guard.dart';
 import 'package:provider/provider.dart';
 import 'package:shared_preferences/shared_preferences.dart';
@@ -131,7 +131,7 @@ class _NewEntryPageState extends State<NewEntryPage> {
     final controller = TextEditingController();
     final result = await showDialog<String>(
       context: context,
-      builder: (context) => AlertDialog(
+      builder: (dialogContext) => AlertDialog(
         title: const Text('New Trip'),
         content: TextField(
           controller: controller,
@@ -140,25 +140,28 @@ class _NewEntryPageState extends State<NewEntryPage> {
         ),
         actions: [
           TextButton(
-            onPressed: () => Navigator.of(context).pop(),
+            onPressed: () => Navigator.of(dialogContext).pop(),
             child: const Text('Cancel'),
           ),
           ElevatedButton(
-            onPressed: () => Navigator.of(context).pop(controller.text.trim()),
+            onPressed: () => Navigator.of(dialogContext).pop(controller.text.trim()),
             child: const Text('Add'),
           ),
         ],
       ),
     );
-    if (!mounted) return;
+    if (!context.mounted) {
+      controller.dispose();
+      return;
+    }
     if (result != null && result.isNotEmpty) {
       final api = context.read<ApiService>();
       final data = context.read<DataService>();
-      final messenger = ScaffoldMessenger.of(context);
+      final messenger = ScaffoldMessenger.maybeOf(context);
       try {
         await api.put('/trips/new', {"trip_name": result});
         await data.fetchTrips();
-        if (!mounted) return;
+        if (!context.mounted) return;
         final trips = data.tripList;
         final match = trips.firstWhere(
           (t) => t.tripName == result,
@@ -169,11 +172,15 @@ class _NewEntryPageState extends State<NewEntryPage> {
         setState(() => _selectedTripId = match.tripId);
         _saveDraft();
       } catch (e) {
-        if (!mounted) return;
-        messenger.showSnackBar(
+        if (!context.mounted) return;
+        messenger?.showSnackBar(
           SnackBar(content: Text('Failed to add trip: $e')),
         );
+      } finally {
+        controller.dispose();
       }
+    } else {
+      controller.dispose();
     }
   }
 
@@ -584,8 +591,11 @@ class _NewEntryPageState extends State<NewEntryPage> {
       final confirmed = await _confirmDuplicateSubmission();
       if (!confirmed) return;
     }
-    setState(() => _submitting = true);
+    if (!mounted) return;
     final api = context.read<ApiService>();
+    final dataService = context.read<DataService>();
+    final messenger = ScaffoldMessenger.maybeOf(context);
+    setState(() => _submitting = true);
     final isEditingExisting = _isEditing && widget.editLegId != null;
 
     try {
@@ -626,9 +636,9 @@ class _NewEntryPageState extends State<NewEntryPage> {
         }
       }
       if (!mounted) return;
-      context.read<DataService>().refreshLegs();
+      dataService.refreshLegs();
       if (!mounted) return;
-      ScaffoldMessenger.of(context).showSnackBar(
+      messenger?.showSnackBar(
         SnackBar(
           content: Text(
             isEditingExisting ? 'Entry updated' : 'Entry submitted',
@@ -639,9 +649,9 @@ class _NewEntryPageState extends State<NewEntryPage> {
       _activeDraftId = null;
     } catch (e) {
       if (!mounted) return;
-      ScaffoldMessenger.of(
-        context,
-      ).showSnackBar(SnackBar(content: Text('Failed to submit: $e')));
+      messenger?.showSnackBar(
+        SnackBar(content: Text('Failed to submit: $e')),
+      );
     } finally {
       if (mounted) setState(() => _submitting = false);
     }
@@ -1279,8 +1289,15 @@ class _NewEntryPageState extends State<NewEntryPage> {
       );
     }
 
-    return WillPopScope(
-      onWillPop: () => _handleExitIntent(),
+    return PopScope(
+      canPop: false,
+      onPopInvokedWithResult: (didPop, _) async {
+        if (didPop) return;
+        final allow = await _handleExitIntent();
+        if (allow && context.mounted) {
+          Navigator.of(context).maybePop();
+        }
+      },
       child: Scaffold(
         appBar: _isEditing
             ? AppBar(
@@ -1288,7 +1305,7 @@ class _NewEntryPageState extends State<NewEntryPage> {
                   icon: const Icon(Icons.arrow_back),
                   onPressed: () async {
                     if (!await _handleExitIntent()) return;
-                    if (!mounted) return;
+                    if (!context.mounted) return;
                     Navigator.of(context).maybePop();
                   },
                 ),
@@ -1507,13 +1524,13 @@ class _DraftListBody extends StatefulWidget {
 }
 
 class _DraftListBodyState extends State<_DraftListBody> {
-  late List<_StoredDraft> _drafts = widget.drafts;
+  late final List<_StoredDraft> _drafts = List.of(widget.drafts);
 
   @override
   Widget build(BuildContext context) {
     return ListView.separated(
       itemCount: _drafts.length,
-      separatorBuilder: (_, __) => const Divider(height: 0),
+      separatorBuilder: (context, _) => const Divider(height: 0),
       itemBuilder: (context, index) {
         final draft = _drafts[index];
         final routeLine = _draftSubtitle(draft);