Added sqlite

lib/models/fuel_entry.dart

@@ -9,6 +9,10 @@ class FuelEntry {
   final String? receiptDriveFileId;
   final DateTime updatedAt;
 
+  /// Soft-delete tombstone: null means active. See [Vehicle.deletedAt] for
+  /// why this is a flag rather than an actual row deletion.
+  final DateTime? deletedAt;
+
   FuelEntry({
     required this.id,
     required this.vehicleId,
@@ -19,6 +23,7 @@ class FuelEntry {
     required this.updatedAt,
     this.receiptImagePath,
     this.receiptDriveFileId,
+    this.deletedAt,
   });
 
   /// True once the receipt photo has been uploaded to Drive and the local
@@ -27,13 +32,16 @@ class FuelEntry {
       receiptImagePath == null && receiptDriveFileId != null;
 
   /// True while a receipt photo exists only locally and still needs to be
-  /// uploaded next sync.
+  /// uploaded next sync. A row in this state is never pushed to Drive as-is
+  /// (a local file path is meaningless on another device) — sync uploads
+  /// the image first, which clears this.
   bool get hasPendingLocalReceipt => receiptImagePath != null;
 
   FuelEntry copyWith({
     String? receiptImagePath,
     String? receiptDriveFileId,
     DateTime? updatedAt,
+    DateTime? deletedAt,
     bool clearReceiptImagePath = false,
   }) {
     return FuelEntry(
@@ -47,32 +55,35 @@ class FuelEntry {
       receiptImagePath:
           clearReceiptImagePath ? null : (receiptImagePath ?? this.receiptImagePath),
       receiptDriveFileId: receiptDriveFileId ?? this.receiptDriveFileId,
+      deletedAt: deletedAt ?? this.deletedAt,
     );
   }
 
-  Map<String, dynamic> toJson() => {
+  Map<String, Object?> toMap() => {
         'id': id,
-        'vehicleId': vehicleId,
-        'date': date.toIso8601String(),
+        'vehicle_id': vehicleId,
+        'date': date.millisecondsSinceEpoch,
         'gallons': gallons,
-        'pricePerGallon': pricePerGallon,
-        'totalCost': totalCost,
-        'receiptImagePath': receiptImagePath,
-        'receiptDriveFileId': receiptDriveFileId,
-        'updatedAt': updatedAt.toIso8601String(),
+        'price_per_gallon': pricePerGallon,
+        'total_cost': totalCost,
+        'receipt_image_path': receiptImagePath,
+        'receipt_drive_file_id': receiptDriveFileId,
+        'updated_at': updatedAt.millisecondsSinceEpoch,
+        'deleted_at': deletedAt?.millisecondsSinceEpoch,
       };
 
-  factory FuelEntry.fromJson(Map<String, dynamic> json) => FuelEntry(
-        id: json['id'] as String,
-        vehicleId: json['vehicleId'] as String,
-        date: DateTime.parse(json['date'] as String),
-        gallons: (json['gallons'] as num).toDouble(),
-        pricePerGallon: (json['pricePerGallon'] as num).toDouble(),
-        totalCost: (json['totalCost'] as num).toDouble(),
-        receiptImagePath: json['receiptImagePath'] as String?,
-        receiptDriveFileId: json['receiptDriveFileId'] as String?,
-        updatedAt: json['updatedAt'] != null
-            ? DateTime.parse(json['updatedAt'] as String)
-            : DateTime.fromMillisecondsSinceEpoch(0),
+  factory FuelEntry.fromMap(Map<String, Object?> map) => FuelEntry(
+        id: map['id'] as String,
+        vehicleId: map['vehicle_id'] as String,
+        date: DateTime.fromMillisecondsSinceEpoch(map['date'] as int),
+        gallons: (map['gallons'] as num).toDouble(),
+        pricePerGallon: (map['price_per_gallon'] as num).toDouble(),
+        totalCost: (map['total_cost'] as num).toDouble(),
+        receiptImagePath: map['receipt_image_path'] as String?,
+        receiptDriveFileId: map['receipt_drive_file_id'] 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)
+            : null,
       );
 }