fix(inventory): 상세 편집 플로우 안정화

- inbound/outbound/rental controller에 fetchTransactionDetail을 추가해 상세 동기화를 지원

- 각 페이지 초기화 시 결재 초안 로딩 권한을 PermissionScope에서 확인하도록 수정

- 상세 패널의 수정 버튼이 모달과 연동되도록 흐름을 정리하고 생성/수정 후 상세 데이터를 재조회

- 기존 결재 메모 필드는 등록 이후 수정 불가하도록 UI와 입력 상태를 비활성화

- 신규 상세-수정 위젯 테스트와 리포지토리 스텁 fetchDetail 구현을 추가

- flutter analyze, flutter test를 실행해 회귀를 점검

lib/features/inventory/rental/presentation/controllers/rental_controller.dart

@@ -262,6 +262,24 @@ class RentalController extends ChangeNotifier {
     );
   }
 
+  /// 단일 대여/반납 트랜잭션 상세를 조회한다.
+  Future<RentalRecord?> fetchTransactionDetail(
+    int id, {
+    List<String> include = const ['lines', 'customers', 'approval'],
+  }) async {
+    try {
+      final transaction = await _transactionRepository.fetchDetail(
+        id,
+        include: include,
+      );
+      return RentalRecord.fromTransaction(transaction);
+    } catch (error, stackTrace) {
+      debugPrint('[RentalController] 상세 조회 실패(id=$id): $error');
+      debugPrintStack(stackTrace: stackTrace);
+      return null;
+    }
+  }
+
   void _persistApprovalDraft(StockTransactionApprovalInput approval) {
     final useCase = _saveDraftUseCase;
     if (useCase == null) {

lib/features/inventory/rental/presentation/pages/rental_page.dart

@@ -162,7 +162,7 @@ class _RentalPageState extends State<RentalPage> {
     Future.microtask(() async {
       await controller.loadStatusOptions();
       final requester = _resolveCurrentWriter();
-      if (requester != null) {
+      if (requester != null && _canRestoreApprovalDrafts) {
         await controller.loadApprovalDraftFromServer(requesterId: requester.id);
       }
       final hasTypes = await controller.resolveTransactionTypes();
@@ -175,6 +175,17 @@ class _RentalPageState extends State<RentalPage> {
     });
   }
 
+  bool get _canRestoreApprovalDrafts {
+    final getIt = GetIt.I;
+    if (!getIt.isRegistered<PermissionManager>()) {
+      return false;
+    }
+    return getIt<PermissionManager>().can(
+      PermissionResources.approvals,
+      PermissionAction.view,
+    );
+  }
+
   void _handleControllerChanged() {
     if (!mounted) {
       return;
@@ -948,7 +959,7 @@ class _RentalPageState extends State<RentalPage> {
   }
 
   List<Widget> _buildDetailActions(RentalRecord record) {
-    final isProcessing = _isProcessing(record.id) || _isLoading;
+    final isProcessing = _isProcessing(record.id);
     final actions = <Widget>[];
 
     if (_canSubmit(record)) {
@@ -994,12 +1005,7 @@ class _RentalPageState extends State<RentalPage> {
     actions.add(
       ShadButton.outline(
         leading: const Icon(lucide.LucideIcons.pencil, size: 16),
-        onPressed: isProcessing
-            ? null
-            : () {
-                Navigator.of(context).maybePop();
-                _handleEdit(record);
-              },
+        onPressed: isProcessing ? null : () => _openEditFromDetail(record),
         child: const Text('수정'),
       ),
     );
@@ -1007,6 +1013,17 @@ class _RentalPageState extends State<RentalPage> {
     return actions;
   }
 
+  void _openEditFromDetail(RentalRecord record) {
+    final navigator = Navigator.of(context, rootNavigator: true);
+    navigator.pop();
+    WidgetsBinding.instance.addPostFrameCallback((_) async {
+      if (!mounted) {
+        return;
+      }
+      await _handleEdit(record, reopenOnCancel: true);
+    });
+  }
+
   Future<void> _handleCreate() async {
     final record = await _showRentalFormDialog();
     if (record != null) {
@@ -1014,10 +1031,15 @@ class _RentalPageState extends State<RentalPage> {
     }
   }
 
-  Future<void> _handleEdit(RentalRecord record) async {
+  Future<void> _handleEdit(
+    RentalRecord record, {
+    bool reopenOnCancel = false,
+  }) async {
     final updated = await _showRentalFormDialog(initial: record);
     if (updated != null) {
       _selectRecord(updated, openDetail: true);
+    } else if (reopenOnCancel) {
+      _selectRecord(record, openDetail: true);
     }
   }
 
@@ -1805,6 +1827,22 @@ class _RentalPageState extends State<RentalPage> {
         return;
       }
 
+      Future<RentalRecord?> resolveUpdatedRecord(int? id) async {
+        if (id == null) {
+          return null;
+        }
+        final detail = await controller.fetchTransactionDetail(id);
+        if (detail != null) {
+          return detail;
+        }
+        for (final record in controller.records) {
+          if (record.id == id) {
+            return record;
+          }
+        }
+        return null;
+      }
+
       final selectedLookup =
           rentalTypeValue.value == RentalTableSpec.rentalTypes.last
           ? (_returnTransactionType ?? controller.returnTransactionType)
@@ -1898,7 +1936,6 @@ class _RentalPageState extends State<RentalPage> {
             ),
             refreshAfter: false,
           );
-          result = updated;
           final currentLines =
               initialRecord.raw?.lines ?? const <StockTransactionLine>[];
           final currentCustomers =
@@ -1922,6 +1959,8 @@ class _RentalPageState extends State<RentalPage> {
             );
           }
           await controller.refresh();
+          final refreshed = await resolveUpdatedRecord(transactionId);
+          result = refreshed ?? updated;
           updateSaving(false);
           if (!mounted) {
             return;
@@ -1993,7 +2032,8 @@ class _RentalPageState extends State<RentalPage> {
             approval: approvalInput,
           ),
         );
-        result = created;
+        final refreshed = await resolveUpdatedRecord(created.id);
+        result = refreshed ?? created;
         updateSaving(false);
         if (!mounted) {
           return;
@@ -2329,9 +2369,26 @@ class _RentalPageState extends State<RentalPage> {
                       width: 500,
                       child: _FormFieldLabel(
                         label: '결재 메모',
-                        child: ShadInput(
-                          controller: approvalNoteController,
-                          maxLines: 2,
+                        child: Column(
+                          crossAxisAlignment: CrossAxisAlignment.start,
+                          children: [
+                            ShadInput(
+                              controller: approvalNoteController,
+                              maxLines: 2,
+                              readOnly: initial != null,
+                              enabled: initial == null,
+                            ),
+                            if (initial != null)
+                              Padding(
+                                padding: const EdgeInsets.only(top: 6),
+                                child: Text(
+                                  '등록된 결재 메모는 수정할 수 없습니다.',
+                                  style: theme.textTheme.small.copyWith(
+                                    color: theme.colorScheme.mutedForeground,
+                                  ),
+                                ),
+                              ),
+                          ],
                         ),
                       ),
                     ),