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

apps/packages/data_connect/lib/src/mocks/business_repository_mock.dart

@@ -25,4 +25,30 @@ class BusinessRepositoryMock {
       ),
     ];
   }
-}
+
+  Future<Hub> createHub({
+    required String businessId,
+    required String name,
+    required String address,
+  }) async {
+    await Future.delayed(const Duration(milliseconds: 500));
+    return Hub(
+      id: 'hub_${DateTime.now().millisecondsSinceEpoch}',
+      businessId: businessId,
+      name: name,
+      address: address,
+      status: HubStatus.active,
+    );
+  }
+
+  Future<void> deleteHub(String id) async {
+    await Future.delayed(const Duration(milliseconds: 300));
+  }
+
+  Future<void> assignNfcTag({
+    required String hubId,
+    required String nfcTagId,
+  }) async {
+    await Future.delayed(const Duration(milliseconds: 500));
+  }
+}