feat: add remote pull and push

lib/models/bar_tab.dart

@@ -7,6 +7,7 @@ class BarTab {
   final String status;
   final DateTime openedAt;
   final DateTime? closedAt;
+  final int version;
   final List<TabItem> items;
 
   const BarTab({
@@ -14,6 +15,7 @@ class BarTab {
     required this.customerName,
     required this.status,
     required this.openedAt,
+    this.version = 0,
     required this.items,
     this.closedAt,
   });
@@ -41,6 +43,7 @@ class BarTab {
           status == other.status &&
           openedAt == other.openedAt &&
           closedAt == other.closedAt &&
+          version == other.version &&
           listEquals(items, other.items);
 
   @override
@@ -50,6 +53,7 @@ class BarTab {
         status,
         openedAt,
         closedAt,
+        version,
         Object.hashAll(items),
       );
 }

lib/models/payment_method.dart

@@ -1,6 +1,7 @@
 enum PaymentMethod {
   cash('cash', 'Cash', 'Cash payment'),
-  payconiq('payconiq', 'Payconiq', 'Payconiq QR payment');
+  payconiq('payconiq', 'Payconiq', 'Payconiq QR payment'),
+  paymentPending('payment_pending', 'Payment pending', 'Unpaid remote close');
 
   final String value;
   final String label;

lib/models/remote_command.dart

@@ -0,0 +1,144 @@
+class RemoteCommand {
+  final String id;
+  final String type;
+  final String tabId;
+  final int expectedVersion;
+  final String paymentMethod;
+  final String requestedBy;
+  final DateTime createdAt;
+
+  const RemoteCommand({
+    required this.id,
+    required this.type,
+    required this.tabId,
+    required this.expectedVersion,
+    required this.paymentMethod,
+    required this.requestedBy,
+    required this.createdAt,
+  });
+
+  factory RemoteCommand.fromJson(Map<String, dynamic> json) {
+    return RemoteCommand(
+      id: json['id'] as String,
+      type: json['type'] as String,
+      tabId: json['tabId'] as String,
+      expectedVersion: json['expectedVersion'] as int,
+      paymentMethod: json['paymentMethod'] as String? ?? 'cash',
+      requestedBy: json['requestedBy'] as String? ?? '',
+      createdAt: DateTime.parse(json['createdAt'] as String),
+    );
+  }
+
+  bool get isExpired {
+    final cutoff = DateTime.now().subtract(const Duration(hours: 24));
+    return createdAt.isBefore(cutoff);
+  }
+}
+
+class SyncResponse {
+  final List<RemoteCommand> commands;
+  final String? cursor;
+  final List<String> plannedTabNames;
+
+  SyncResponse({
+    required this.commands,
+    this.cursor,
+    this.plannedTabNames = const [],
+  });
+
+  factory SyncResponse.fromJson(Map<String, dynamic> json) {
+    final commandsList = (json['commands'] as List<dynamic>?)
+            ?.map((e) => RemoteCommand.fromJson(e as Map<String, dynamic>))
+            .toList() ??
+        [];
+    return SyncResponse(
+      commands: commandsList,
+      cursor: json['cursor'] as String?,
+      plannedTabNames: (json['plannedTabNames'] as List<dynamic>?)
+              ?.map((e) => e as String)
+              .toList() ??
+          [],
+    );
+  }
+}
+
+class SnapshotTab {
+  final String id;
+  final String customerName;
+  final int version;
+  final int totalInCents;
+  final int itemCount;
+
+  const SnapshotTab({
+    required this.id,
+    required this.customerName,
+    required this.version,
+    required this.totalInCents,
+    required this.itemCount,
+  });
+
+  Map<String, dynamic> toJson() => {
+        'id': id,
+        'customerName': customerName,
+        'version': version,
+        'totalInCents': totalInCents,
+        'itemCount': itemCount,
+      };
+}
+
+class SyncRequest {
+  final String deviceId;
+  final String? cursor;
+  final List<SnapshotTab> openTabs;
+
+  const SyncRequest({
+    required this.deviceId,
+    this.cursor,
+    required this.openTabs,
+  });
+
+  Map<String, dynamic> toJson() => {
+        'deviceId': deviceId,
+        if (cursor != null) 'cursor': cursor,
+        'openTabs': openTabs.map((t) => t.toJson()).toList(),
+      };
+}
+
+class CommandAck {
+  final String commandId;
+  final String status;
+  final String? result;
+
+  const CommandAck({
+    required this.commandId,
+    required this.status,
+    this.result,
+  });
+
+  Map<String, dynamic> toJson() => {
+        'commandId': commandId,
+        'status': status,
+        if (result != null) 'result': result,
+      };
+}
+
+enum RemoteSyncEventType {
+  tabClosedRemotely,
+  syncCompleted,
+  syncFailed,
+  conflict,
+}
+
+class RemoteSyncEvent {
+  final RemoteSyncEventType type;
+  final String? tabCustomerName;
+  final String? requestedBy;
+  final String? message;
+
+  const RemoteSyncEvent({
+    required this.type,
+    this.tabCustomerName,
+    this.requestedBy,
+    this.message,
+  });
+}

lib/models/venue.dart

@@ -0,0 +1,11 @@
+class Venue {
+  final String id;
+  final String name;
+
+  const Venue({required this.id, required this.name});
+
+  factory Venue.fromJson(Map<String, dynamic> json) => Venue(
+        id: json['id'] as String,
+        name: json['name'] as String,
+      );
+}