feat(dept): 科室管理——flw_dept/flw_dept_member 组+成员模型取代单用户映射行（议题3，拍板D1选B）

- deptKey=本地自增 id；source_group_id 幂等（一键拉取=初始化/刷新语义，不重复建组）；不做存量迁移
- 四处读源全部切新表：AssigneeResolver（宽容口径：deptKey 不存在/停用返回空，图示/轨迹不炸）、
  enabledDeptKeys 发布校验白名单、DeptLabelSupport 唯一出口（图示科室视图+轨迹富化）、编辑器 deptList 聚合
- /admin/dept/* 全套端点（CRUD/成员/拉取预览导入）；旧 /map/* 映射 CRUD 端点删除
  （保留 /map/lookupUser 选人检索与 /user/teacherTree）；flw_assignee_map 实体/表保留不删
- IT 种子切源（FlowTestSupport tag→deptKey 注册表，用例主体零改动）；全量 191 绿；E2E 22/22
  （local-debug/four-topics-e-e2e.py，含切源后果验证与生产盘点 SQL）

src/main/java/com/yunhai/flowcenter/service/FlowQueryService.java

@@ -11,7 +11,6 @@ import com.yunhai.flowcenter.entity.FlwRouteLog;
 import com.yunhai.flowcenter.entity.FlwTask;
 import com.yunhai.flowcenter.enums.FlwEnums;
 import com.yunhai.flowcenter.model.FlowModels;
-import com.yunhai.flowcenter.repository.FlwAssigneeMapRepository;
 import com.yunhai.flowcenter.repository.FlwBranchRepository;
 import com.yunhai.flowcenter.repository.FlwCcRepository;
 import com.yunhai.flowcenter.repository.FlwDefRepository;
@@ -47,7 +46,7 @@ public class FlowQueryService {
     private final FlwCcRepository ccRepository;
     private final FlwRouteLogRepository routeLogRepository;
     private final FlwDefRepository defRepository;
-    private final FlwAssigneeMapRepository mapRepository;
+    private final FlowDeptAdminService deptAdminService;
     private final FlowEngine flowEngine;
 
     public BasePageResult<FlowModels.InstanceItem> pageMy(Long schId, Integer submitterId,
@@ -476,7 +475,7 @@ public class FlowQueryService {
         }
         row.put("deptKey", assignee.deptKey);
         String deptName = deptNames.computeIfAbsent(assignee.deptKey,
-                k -> DeptLabelSupport.mappedDeptName(mapRepository.findEnabled(schId, k)));
+                k -> DeptLabelSupport.deptName(deptAdminService, schId, k));
         if (deptName != null) {
             row.put("deptName", deptName);
         }