fix(inventory): 파트너 연동 및 상세 모달 동작 안정화

- 입고 레코드에 파트너 식별자와 고객 요약을 캐싱하고 상세 칩으로 노출

- 입고 등록 모달에서 파트너 선택 복원과 고객 동기화를 지원하며 취소 시 상세를 복귀하도록 수정

- 재고 컨트롤러에 고객 동기화 유틸리티와 결재 상태 로딩을 추가하고 단위 테스트를 확장

- 제품·파트너 자동완성 위젯을 재작성해 초기 로딩, 검색, 외부 컨트롤러 동기화를 안정화

- 재고 상세/공통 모달 닫기와 출고·대여 편집 모달의 네비게이터 호출을 루트 기준으로 통일

- 테스트: flutter analyze, flutter test (기존 레이아웃 검증 케이스 실패 지속)

test/features/inventory/inbound/presentation/controllers/inbound_controller_test.dart

@@ -9,6 +9,7 @@ import 'package:superport_v2/features/inventory/transactions/domain/entities/sto
 import 'package:superport_v2/features/inventory/transactions/domain/entities/stock_transaction_input.dart';
 import 'package:superport_v2/features/inventory/transactions/domain/repositories/stock_transaction_repository.dart';
 import 'package:superport_v2/features/inventory/lookups/domain/repositories/inventory_lookup_repository.dart';
+import 'package:superport_v2/features/inventory/transactions/presentation/services/transaction_detail_sync_service.dart';
 
 class _MockStockTransactionRepository extends Mock
     implements StockTransactionRepository {}
@@ -19,6 +20,9 @@ class _MockInventoryLookupRepository extends Mock
 class _MockTransactionLineRepository extends Mock
     implements TransactionLineRepository {}
 
+class _MockTransactionCustomerRepository extends Mock
+    implements TransactionCustomerRepository {}
+
 class _FakeStockTransactionCreateInput extends Fake
     implements StockTransactionCreateInput {}
 
@@ -28,26 +32,39 @@ class _FakeStockTransactionUpdateInput extends Fake
 class _FakeStockTransactionListFilter extends Fake
     implements StockTransactionListFilter {}
 
+class _FakeTransactionCustomerCreateInput extends Fake
+    implements TransactionCustomerCreateInput {}
+
+class _FakeTransactionCustomerUpdateInput extends Fake
+    implements TransactionCustomerUpdateInput {}
+
 void main() {
   group('InboundController', () {
     late StockTransactionRepository transactionRepository;
     late InventoryLookupRepository lookupRepository;
     late TransactionLineRepository lineRepository;
+    late TransactionCustomerRepository customerRepository;
     late InboundController controller;
 
     setUpAll(() {
       registerFallbackValue(_FakeStockTransactionCreateInput());
       registerFallbackValue(_FakeStockTransactionUpdateInput());
       registerFallbackValue(_FakeStockTransactionListFilter());
+      registerFallbackValue(_FakeTransactionCustomerCreateInput());
+      registerFallbackValue(_FakeTransactionCustomerUpdateInput());
+      registerFallbackValue(<TransactionCustomerCreateInput>[]);
+      registerFallbackValue(<TransactionCustomerUpdateInput>[]);
     });
 
     setUp(() {
       transactionRepository = _MockStockTransactionRepository();
       lookupRepository = _MockInventoryLookupRepository();
       lineRepository = _MockTransactionLineRepository();
+      customerRepository = _MockTransactionCustomerRepository();
       controller = InboundController(
         transactionRepository: transactionRepository,
         lineRepository: lineRepository,
+        customerRepository: customerRepository,
         lookupRepository: lookupRepository,
       );
     });
@@ -156,6 +173,30 @@ void main() {
       verify(() => transactionRepository.delete(transaction.id!)).called(1);
     });
 
+    test('syncTransactionCustomers는 계획에 따라 저장소를 호출한다', () async {
+      when(
+        () => customerRepository.updateCustomers(any(), any()),
+      ).thenAnswer((_) async {});
+      when(
+        () => customerRepository.deleteCustomer(any()),
+      ).thenAnswer((_) async {});
+      when(
+        () => customerRepository.addCustomers(any(), any()),
+      ).thenAnswer((_) async {});
+
+      final plan = TransactionCustomerSyncPlan(
+        createdCustomers: [TransactionCustomerCreateInput(customerId: 7)],
+        updatedCustomers: [TransactionCustomerUpdateInput(id: 2, note: '메모')],
+        deletedCustomerIds: const [5],
+      );
+
+      await controller.syncTransactionCustomers(42, plan);
+
+      verify(() => customerRepository.updateCustomers(42, any())).called(1);
+      verify(() => customerRepository.deleteCustomer(5)).called(1);
+      verify(() => customerRepository.addCustomers(42, any())).called(1);
+    });
+
     test('submitTransaction은 refreshAfter가 true일 때 목록을 다시 불러온다', () async {
       final filter = StockTransactionListFilter(transactionTypeId: 1);
       final initial = _buildTransaction();