feat(frontend): 승인 템플릿 API 통합 및 디버그 로그인 확장

- docs 폴더 문서를 최신 API 계약으로 갱신하고 가이드를 다듬었다\n- approvals data/presentation 레이어를 API v4 스펙에 맞춰 리팩터링했다\n- approver 자동완성 위젯을 신규 공유 레포지토리에 맞춰 교체하고 UX를 보강했다\n- inventory/rental 페이지 테이블 초기화 시 승인 기준 연동을 정비했다\n- 로그인 페이지 디버그 버튼을 tera/exa 계정으로 분리해 QA 로그인을 단순화했다\n- get_it 등록과 테스트 케이스를 신규 공유 리포지토리에 맞춰 업데이트했다

lib/features/approvals/template/presentation/pages/approval_template_page.dart

@@ -1,6 +1,7 @@
 import 'package:flutter/material.dart';
 import 'package:get_it/get_it.dart';
 import 'package:lucide_icons_flutter/lucide_icons.dart' as lucide;
+import 'package:intl/intl.dart' as intl;
 import 'package:shadcn_ui/shadcn_ui.dart';
 
 import '../../../../../core/config/environment.dart';
@@ -15,6 +16,7 @@ import '../../../domain/entities/approval_template.dart';
 import '../../../domain/repositories/approval_template_repository.dart';
 import '../../../domain/usecases/apply_approval_template_use_case.dart';
 import '../../../domain/usecases/save_approval_template_use_case.dart';
+import '../../../../auth/application/auth_service.dart';
 import '../controllers/approval_template_controller.dart';
 
 /// 결재 템플릿 관리 페이지. 기능 플래그에 따라 준비중 화면을 노출한다.
@@ -69,7 +71,7 @@ class _ApprovalTemplateEnabledPageState
   late final ApprovalTemplateController _controller;
   final TextEditingController _searchController = TextEditingController();
   final FocusNode _searchFocus = FocusNode();
-  final DateFormat _dateFormat = DateFormat('yyyy-MM-dd HH:mm');
+  final intl.DateFormat _dateFormat = intl.DateFormat('yyyy-MM-dd HH:mm');
   String? _lastError;
   static const _pageSizeOptions = [10, 20, 50];
 
@@ -354,6 +356,50 @@ class _ApprovalTemplateEnabledPageState
     _searchFocus.requestFocus();
   }
 
+  String _generateTemplateCode() {
+    final authService = GetIt.I<AuthService>();
+    final session = authService.session;
+    String normalizedEmployee = '';
+
+    final candidateValues = <String?>[
+      session?.user.employeeNo,
+      session?.user.email,
+      session?.user.name,
+    ];
+    for (final candidate in candidateValues) {
+      if (candidate == null) {
+        continue;
+      }
+      var source = candidate.trim();
+      final atIndex = source.indexOf('@');
+      if (atIndex > 0) {
+        source = source.substring(0, atIndex);
+      }
+      final normalized = source.toUpperCase().replaceAll(
+        RegExp(r'[^A-Z0-9]'),
+        '',
+      );
+      if (normalized.isNotEmpty) {
+        normalizedEmployee = normalized;
+        break;
+      }
+    }
+    if (normalizedEmployee.isEmpty && session?.user.id != null) {
+      normalizedEmployee = session!.user.id.toString();
+    }
+
+    final suffixSource = normalizedEmployee.isEmpty
+        ? '0000'
+        : normalizedEmployee;
+    final suffix = suffixSource.length >= 4
+        ? suffixSource.substring(suffixSource.length - 4)
+        : suffixSource.padLeft(4, '0');
+    final timestamp = intl.DateFormat(
+      'yyMMddHHmmssSSS',
+    ).format(DateTime.now().toUtc());
+    return 'AP_TEMP_${suffix}_$timestamp';
+  }
+
   Future<void> _openTemplatePreview(int templateId) async {
     showDialog<void>(
       context: context,
@@ -530,7 +576,9 @@ class _ApprovalTemplateEnabledPageState
   Future<bool?> _openTemplateForm({ApprovalTemplate? template}) async {
     final isEdit = template != null;
     final existingTemplate = template;
-    final codeController = TextEditingController(text: template?.code ?? '');
+    final codeController = TextEditingController(
+      text: isEdit ? existingTemplate!.code : _generateTemplateCode(),
+    );
     final nameController = TextEditingController(text: template?.name ?? '');
     final descriptionController = TextEditingController(
       text: template?.description ?? '',
@@ -573,7 +621,7 @@ class _ApprovalTemplateEnabledPageState
           )
           .toList();
       final input = ApprovalTemplateInput(
-        code: isEdit ? existingTemplate?.code : codeValue,
+        code: isEdit ? existingTemplate!.code : codeValue,
         name: nameValue,
         description: descriptionController.text.trim().isEmpty
             ? null
@@ -583,16 +631,11 @@ class _ApprovalTemplateEnabledPageState
             : noteController.text.trim(),
         isActive: statusNotifier.value,
       );
-      if (isEdit && existingTemplate == null) {
-        modalSetState?.call(() => errorText = '템플릿 정보를 불러오지 못했습니다.');
-        modalSetState?.call(() => isSaving = false);
-        return;
-      }
 
       modalSetState?.call(() => isSaving = true);
 
-      final success = isEdit && existingTemplate != null
-          ? await _controller.update(existingTemplate.id, input, stepInputs)
+      final success = isEdit
+          ? await _controller.update(existingTemplate!.id, input, stepInputs)
           : await _controller.create(input, stepInputs);
       if (success != null && mounted) {
         Navigator.of(context, rootNavigator: true).pop(true);
@@ -622,6 +665,8 @@ class _ApprovalTemplateEnabledPageState
                       label: '템플릿 코드',
                       child: ShadInput(
                         controller: codeController,
+                        readOnly: true,
+                        enabled: false,
                         placeholder: const Text('예: AP_INBOUND'),
                       ),
                     ),