A whole bunch of changes

lib/screens/add_edit_vehicle_screen.dart

@@ -12,11 +12,19 @@ import '../widgets/image_source_sheet.dart';
 import 'vehicle_detail_screen.dart';
 
 /// Add/edit form for a vehicle. Pass an existing [vehicle] to edit it, or
-/// omit it to create a new one.
+/// omit it to create a new one. [promptToCreateForReceipt] is set when this
+/// screen was reached because the user tried to log a receipt with no
+/// vehicle to attach it to yet — it shows an explanatory dialog on arrival
+/// so that's clear, rather than silently landing on the add-vehicle form.
 class AddEditVehicleScreen extends StatefulWidget {
   final Vehicle? vehicle;
+  final bool promptToCreateForReceipt;
 
-  const AddEditVehicleScreen({super.key, this.vehicle});
+  const AddEditVehicleScreen({
+    super.key,
+    this.vehicle,
+    this.promptToCreateForReceipt = false,
+  });
 
   @override
   State<AddEditVehicleScreen> createState() => _AddEditVehicleScreenState();
@@ -39,6 +47,24 @@ class _AddEditVehicleScreenState extends State<AddEditVehicleScreen> {
     super.initState();
     _nicknameController = TextEditingController(text: widget.vehicle?.nickname ?? '');
     _vinController = TextEditingController(text: widget.vehicle?.vin ?? '');
+
+    if (widget.promptToCreateForReceipt) {
+      WidgetsBinding.instance.addPostFrameCallback((_) {
+        if (!mounted) return;
+        showDialog<void>(
+          context: context,
+          builder: (context) => AlertDialog(
+            content: const Text('Create a vehicle to attach receipt'),
+            actions: [
+              TextButton(
+                onPressed: () => Navigator.of(context).pop(),
+                child: const Text('OK'),
+              ),
+            ],
+          ),
+        );
+      });
+    }
   }
 
   @override
@@ -48,8 +74,46 @@ class _AddEditVehicleScreenState extends State<AddEditVehicleScreen> {
     super.dispose();
   }
 
+  void _showVinLocationHelp() {
+    showDialog<void>(
+      context: context,
+      builder: (context) => AlertDialog(
+        title: const Text('Where to find the VIN'),
+        content: SingleChildScrollView(
+          child: Column(
+            mainAxisSize: MainAxisSize.min,
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: [
+              const Text(
+                "It's usually on a sticker in the driver's side door jamb, or on a "
+                'small plate at the base of the windshield.',
+              ),
+              const SizedBox(height: 16),
+              ClipRRect(
+                borderRadius: BorderRadius.circular(8),
+                child: Image.asset('assets/vin_help/door_jamb.jpg'),
+              ),
+              const SizedBox(height: 12),
+              ClipRRect(
+                borderRadius: BorderRadius.circular(8),
+                child: Image.asset('assets/vin_help/windshield.jpg'),
+              ),
+            ],
+          ),
+        ),
+        actions: [
+          TextButton(onPressed: () => Navigator.of(context).pop(), child: const Text('Close')),
+        ],
+      ),
+    );
+  }
+
   Future<void> _scanVin() async {
-    final source = await chooseImageSource(context);
+    final source = await chooseImageSource(
+      context,
+      heading: 'VIN From',
+      onInfoTap: _showVinLocationHelp,
+    );
     if (source == null || !mounted) return;
 
     final picker = ImagePicker();
@@ -89,13 +153,35 @@ class _AddEditVehicleScreenState extends State<AddEditVehicleScreen> {
       await _checkForExistingVin();
     } else if (mounted) {
       ScaffoldMessenger.of(context).showSnackBar(
-        const SnackBar(
-          content: Text("Couldn't read a VIN from that photo. Please enter it manually."),
+        SnackBar(
+          content: const Text("Couldn't read a VIN from that photo. Please enter it manually."),
+          duration: const Duration(seconds: 8),
+          action: recognizedText.trim().isEmpty
+              ? null
+              // Lets you see exactly what the on-device OCR read, rather
+              // than only knowing "no VIN was found in it" — the
+              // difference between "OCR misread a character" and "OCR
+              // read it fine but the VIN pattern itself needs a fix"
+              // isn't visible any other way.
+              : SnackBarAction(label: 'Show Text', onPressed: () => _showRecognizedText(recognizedText)),
         ),
       );
     }
   }
 
+  void _showRecognizedText(String text) {
+    showDialog<void>(
+      context: context,
+      builder: (context) => AlertDialog(
+        title: const Text('Recognized Text'),
+        content: SingleChildScrollView(child: SelectableText(text)),
+        actions: [
+          TextButton(onPressed: () => Navigator.of(context).pop(), child: const Text('Close')),
+        ],
+      ),
+    );
+  }
+
   /// Field-level counterpart to [_checkForExistingVin]'s dialog: catches
   /// "Required" as before, plus flags the field itself as invalid when the
   /// VIN belongs to another active vehicle — excluding this vehicle's own
@@ -160,24 +246,30 @@ class _AddEditVehicleScreenState extends State<AddEditVehicleScreen> {
       _error = null;
     });
 
+    final vin = _vinController.text.trim();
     final nickname = _nicknameController.text.trim();
     final appState = context.read<AppState>();
 
     try {
       if (_isEditing) {
         await appState.updateVehicle(widget.vehicle!.copyWith(
-          vin: _vinController.text.trim(),
+          vin: vin,
           nickname: nickname.isEmpty ? null : nickname,
           clearNickname: nickname.isEmpty,
         ));
       } else {
-        await appState.addVehicle(
-          vin: _vinController.text.trim(),
-          nickname: nickname.isEmpty ? null : nickname,
-        );
+        await appState.addVehicle(vin: vin, nickname: nickname.isEmpty ? null : nickname);
       }
 
-      if (mounted) Navigator.of(context).pop();
+      if (mounted) {
+        // Reached from "log a receipt with no vehicle yet" — once the
+        // vehicle exists, continue straight into the receipt capture flow
+        // the user was actually trying to do, rather than just landing
+        // back on an (again) empty Receipts tab. The caller does the
+        // continuing; this just hands back which vehicle to do it for.
+        final continueToReceipt = !_isEditing && widget.promptToCreateForReceipt;
+        Navigator.of(context).pop(continueToReceipt ? appState.vehicleByVin(vin)?.id : null);
+      }
     } on DuplicateVinException catch (e) {
       setState(() => _error = e.toString());
     } finally {