feat: Implement client hubs management feature, including CRUD operations and NFC tag assignment.

apps/packages/domain/lib/src/entities/business/hub.dart

@@ -26,6 +26,9 @@ class Hub extends Equatable {
   /// Physical address of this hub.
   final String address;
 
+  /// Unique identifier of the NFC tag assigned to this hub.
+  final String? nfcTagId;
+
   /// Operational status.
   final HubStatus status;
 
@@ -34,9 +37,10 @@ class Hub extends Equatable {
     required this.businessId,
     required this.name,
     required this.address,
+    this.nfcTagId,
     required this.status,
   });
 
   @override
-  List<Object?> get props => [id, businessId, name, address, status];
-}
+  List<Object?> get props => [id, businessId, name, address, nfcTagId, status];
+}