Remote sync of webdav

lib/models/vehicle.dart

@@ -1,9 +1,19 @@
 class Vehicle {
+  /// Hidden, immutable, generated primary key — never shown in the UI and
+  /// never editable. This is what fuel entries actually reference and what
+  /// sync merges on, so that [vin] itself is free to be edited without
+  /// breaking those references or losing sync history.
   final String id;
-  final String make;
-  final String model;
-  final String color;
-  final String licensePlate;
+
+  /// The vehicle's identification number. Required and must be unique
+  /// among active (non-deleted) vehicles, but — unlike [id] — the user can
+  /// edit it later (e.g. to fix a typo from a misread VIN scan).
+  final String vin;
+
+  /// User-chosen label, e.g. "Mom's Car" or "Red Ford F-150". Optional —
+  /// when absent, screens fall back to other identifying info instead.
+  final String? nickname;
+
   final DateTime updatedAt;
 
   /// Soft-delete tombstone: null means active. Deleting sets this instead
@@ -15,30 +25,35 @@ class Vehicle {
 
   Vehicle({
     required this.id,
-    required this.make,
-    required this.model,
-    required this.color,
-    required this.licensePlate,
+    required this.vin,
     required this.updatedAt,
+    this.nickname,
     this.deletedAt,
   });
 
-  String get displayName => '$color $make $model ($licensePlate)';
+  /// What screens should show as the vehicle's primary label: the nickname
+  /// if one was given, otherwise the VIN itself.
+  String get displayLabel {
+    final trimmedNickname = nickname?.trim();
+    if (trimmedNickname != null && trimmedNickname.isNotEmpty) {
+      return trimmedNickname;
+    }
+    return vin;
+  }
 
+  /// Note: [id] is intentionally not overridable here — it's the hidden
+  /// identifier, not an editable field.
   Vehicle copyWith({
-    String? make,
-    String? model,
-    String? color,
-    String? licensePlate,
+    String? vin,
+    String? nickname,
+    bool clearNickname = false,
     DateTime? updatedAt,
     DateTime? deletedAt,
   }) {
     return Vehicle(
       id: id,
-      make: make ?? this.make,
-      model: model ?? this.model,
-      color: color ?? this.color,
-      licensePlate: licensePlate ?? this.licensePlate,
+      vin: vin ?? this.vin,
+      nickname: clearNickname ? null : (nickname ?? this.nickname),
       updatedAt: updatedAt ?? this.updatedAt,
       deletedAt: deletedAt ?? this.deletedAt,
     );
@@ -46,20 +61,16 @@ class Vehicle {
 
   Map<String, Object?> toMap() => {
         'id': id,
-        'make': make,
-        'model': model,
-        'color': color,
-        'license_plate': licensePlate,
+        'vin': vin,
+        'nickname': nickname,
         'updated_at': updatedAt.millisecondsSinceEpoch,
         'deleted_at': deletedAt?.millisecondsSinceEpoch,
       };
 
   factory Vehicle.fromMap(Map<String, Object?> map) => Vehicle(
         id: map['id'] as String,
-        make: map['make'] as String,
-        model: map['model'] as String,
-        color: map['color'] as String,
-        licensePlate: map['license_plate'] as String,
+        vin: map['vin'] as String,
+        nickname: map['nickname'] as String?,
         updatedAt: DateTime.fromMillisecondsSinceEpoch(map['updated_at'] as int, isUtc: true),
         deletedAt: map['deleted_at'] != null
             ? DateTime.fromMillisecondsSinceEpoch(map['deleted_at'] as int, isUtc: true)