재고 상세 다이얼로그화 및 마스터 레이아웃 개선

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

@@ -264,5 +264,47 @@ void main() {
       expect(find.text('C-100'), findsOneWidget);
       verify(() => repository.create(any())).called(1);
     });
+
+    testWidgets('좁은 폭에서도 오버플로 없이 렌더링', (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: [
+            Customer(
+              id: 1,
+              customerCode: 'C-SMALL',
+              customerName: '좁은 화면 고객',
+              isPartner: false,
+              isGeneral: true,
+            ),
+          ],
+          page: 1,
+          pageSize: 20,
+          total: 1,
+        ),
+      );
+
+      await tester.pumpWidget(
+        _buildApp(
+          Center(
+            child: SizedBox(
+              width: 260,
+              child: CustomerPage(routeUri: Uri(path: '/masters/customers')),
+            ),
+          ),
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      expect(tester.takeException(), isNull);
+    });
   });
 }