feat: 完善报销单审批流程及退回原因追踪

新增直属领导审批通过接口和审批待办列表查询，报销单退回
支持原因码分类和审批环节标记，优化票据附件去重和路径
回退查找，前端新增退回原因对话框、审批收件箱和工作台
图标组件，补充工具函数和单元测试覆盖。

web/src/views/EmployeeManagementView.vue

@@ -287,12 +287,10 @@
                     class="history-row"
                   >
                     <strong>{{ item.action }}</strong>
-                    <div class="history-row-meta">
-                      <span class="history-row-owner">{{ item.owner }}</span>
-                      <small class="history-row-time">{{
-                        formatEmployeeHistoryTime(item.time || item.occurredAt)
-                      }}</small>
-                    </div>
+                    <span class="history-row-owner">{{ item.owner }}</span>
+                    <small class="history-row-time">{{
+                      formatEmployeeHistoryTime(item.time || item.occurredAt)
+                    }}</small>
                   </div>
                   <p v-if="!recentEmployeeHistory.length" class="manager-picker-empty">
                     暂无变更记录