second commit

lib/domain/repositories/customer_repository.dart

@@ -0,0 +1,24 @@
+import '../entities/customer.dart';
+
+abstract class CustomerRepository {
+  /// Primary lookup on the Existing Customer screen.
+  Future<Customer?> findByMobile(String mobile);
+
+  Future<Customer?> findById(String id);
+
+  Future<Customer> create(Customer customer);
+
+  Future<Customer> update(Customer customer);
+
+  /// Applies loyalty and lifetime-spend changes once a sale completes.
+  Future<Customer> recordSale({
+    required String customerId,
+    required double amount,
+    required int pointsEarned,
+    required int pointsRedeemed,
+  });
+
+  Future<List<Customer>> search(String query);
+
+  Future<List<Customer>> recent({int limit = 20});
+}