결재 템플릿 단계 적용 구현

- ApprovalTemplate 엔티티·DTO·원격 리포지토리 추가
- ApprovalController에 템플릿 로딩/적용 상태와 assignSteps 호출 연동
- ApprovalPage 단계 탭에 템플릿 선택 UI 및 적용 확인 다이얼로그 구현
- 템플릿 적용 단위 테스트와 IMPLEMENTATION_TASKS 현황 갱신

lib/features/approvals/domain/repositories/approval_repository.dart

@@ -0,0 +1,39 @@
+import 'package:superport_v2/core/common/models/paginated_result.dart';
+
+import '../entities/approval.dart';
+
+abstract class ApprovalRepository {
+  Future<PaginatedResult<Approval>> list({
+    int page = 1,
+    int pageSize = 20,
+    String? query,
+    String? status,
+    DateTime? from,
+    DateTime? to,
+    bool includeHistories = false,
+    bool includeSteps = false,
+  });
+
+  Future<Approval> fetchDetail(
+    int id, {
+    bool includeSteps = true,
+    bool includeHistories = true,
+  });
+
+  /// 활성화된 결재 행위(approve/reject/comment 등) 목록 조회
+  Future<List<ApprovalAction>> listActions({bool activeOnly = true});
+
+  /// 결재 단계에 행위를 적용하고 최신 결재 정보를 반환
+  Future<Approval> performStepAction(ApprovalStepActionInput input);
+
+  /// 결재 단계 일괄 생성/재배치
+  Future<Approval> assignSteps(ApprovalStepAssignmentInput input);
+
+  Future<Approval> create(ApprovalInput input);
+
+  Future<Approval> update(int id, ApprovalInput input);
+
+  Future<void> delete(int id);
+
+  Future<Approval> restore(int id);
+}

lib/features/approvals/domain/repositories/approval_template_repository.dart

@@ -0,0 +1,7 @@
+import '../entities/approval_template.dart';
+
+abstract class ApprovalTemplateRepository {
+  Future<List<ApprovalTemplate>> list({bool activeOnly = true});
+
+  Future<ApprovalTemplate> fetchDetail(int id, {bool includeSteps = true});
+}