전역 구조 리팩터링 및 테스트 확장

test/features/masters/customer/presentation/pages/customer_page_test.dart

@@ -138,6 +138,48 @@ void main() {
       expect(find.text('고객사명을 입력하세요.'), findsOneWidget);
     });
 
+    testWidgets('우편번호를 수동 입력하면 검색 안내를 노출한다', (tester) async {
+      when(
+        () => repository.list(
+          page: any(named: 'page'),
+          pageSize: any(named: 'pageSize'),
+          query: any(named: 'query'),
+          isPartner: any(named: 'isPartner'),
+          isGeneral: any(named: 'isGeneral'),
+          isActive: any(named: 'isActive'),
+        ),
+      ).thenAnswer(
+        (_) async => PaginatedResult<Customer>(
+          items: const [],
+          page: 1,
+          pageSize: 20,
+          total: 0,
+        ),
+      );
+
+      await tester.pumpWidget(
+        _buildApp(CustomerPage(routeUri: Uri(path: '/masters/customers'))),
+      );
+      await tester.pumpAndSettle();
+
+      await tester.tap(find.text('신규 등록'));
+      await tester.pumpAndSettle();
+
+      final fields = find.descendant(
+        of: find.byType(Dialog),
+        matching: find.byType(EditableText),
+      );
+
+      await tester.enterText(fields.at(0), 'C-200');
+      await tester.enterText(fields.at(1), '검색 필요 고객');
+      await tester.enterText(fields.at(4), '06000');
+
+      await tester.tap(find.text('등록'));
+      await tester.pump();
+
+      expect(find.text('우편번호 검색으로 주소를 선택하세요.'), findsOneWidget);
+    });
+
     testWidgets('신규 등록 성공 시 repository.create 호출', (tester) async {
       var listCallCount = 0;
       when(