fix: 修复页面间状态丢失问题并优化选择页面

- 修复选择审批人后再选择抄送人导致状态丢失的问题
- 使用独立的 sessionStorage key (selectedApprovers, selectedCc)
- 组件每次挂载时从 sessionStorage 恢复状态
- 只在提交/保存成功后清除 sessionStorage
- 优化人员选择页面布局和样式
- 更新 CLAUDE.md 文档记录问题和解决方案

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/pages/business-trip/detail.module.css

@@ -1,39 +1,161 @@
 .detail {
+  min-height: 100vh;
+  background: #f5f5f5;
+  padding-bottom: 80px;
+}
+
+.loading {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  min-height: 50vh;
+  color: #999;
+}
+
+.content {
   padding: 16px;
 }
 
-.card {
-  background: #fff;
-  border-radius: 8px;
-  padding: 16px;
+.statusCard {
   margin-bottom: 16px;
 }
 
-.card h2 {
-  margin: 0 0 12px 0;
-  font-size: 16px;
+.statusHeader {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  margin-bottom: 16px;
+  padding-bottom: 12px;
+  border-bottom: 1px solid #f0f0f0;
 }
 
-.actions {
+.reason {
+  font-size: 18px;
+  font-weight: 500;
+  color: #333;
+  flex: 1;
+  margin-right: 12px;
+}
+
+.statusInfo {
+  display: flex;
+  flex-direction: column;
+  gap: 12px;
+}
+
+.infoItem {
+  display: flex;
+}
+
+.label {
+  color: #999;
+  font-size: 14px;
+  width: 80px;
+  flex-shrink: 0;
+}
+
+.value {
+  color: #333;
+  font-size: 14px;
+  flex: 1;
+}
+
+.section {
+  margin-bottom: 16px;
+}
+
+.itineraries {
+  display: flex;
+  flex-direction: column;
+  gap: 16px;
+}
+
+.itineraryItem {
+  background: #fafafa;
+  border-radius: 8px;
+  padding: 12px;
+}
+
+.itineraryHeader {
+  font-weight: 500;
+  color: #333;
+  margin-bottom: 12px;
+}
+
+.itineraryContent {
+  display: flex;
+  flex-direction: column;
+  gap: 8px;
+}
+
+.row {
+  display: flex;
+  font-size: 14px;
+}
+
+.timeline {
+  padding: 16px 0;
+}
+
+.timelineItem {
+  position: relative;
+}
+
+.timelineTitle {
+  font-weight: 500;
+  color: #333;
+  margin-bottom: 4px;
+}
+
+.timelineTime {
+  font-size: 12px;
+  color: #999;
+}
+
+.timelineDesc {
+  font-size: 12px;
+  color: #666;
+}
+
+.timelineIconSuccess {
+  color: #52c41a;
+  font-size: 18px;
+  margin-right: 8px;
+}
+
+.timelineIconError {
+  color: #ff4d4f;
+  font-size: 18px;
+  margin-right: 8px;
+}
+
+.empty {
+  text-align: center;
+  color: #999;
+  padding: 20px 0;
+  font-size: 14px;
+}
+
+.footer {
+  position: fixed;
+  bottom: 0;
+  left: 0;
+  right: 0;
+  background: #fff;
+  padding: 12px 16px;
+  box-shadow: 0 -2px 8px rgba(0, 0, 0, 0.1);
   display: flex;
   gap: 12px;
 }
 
-.actions button {
+.footer button {
   flex: 1;
-  padding: 12px;
-  border: none;
-  border-radius: 6px;
-  font-size: 16px;
-  cursor: pointer;
 }
 
-.approveBtn {
-  background: #52c41a;
-  color: #fff;
+:global(.adm-card-body) {
+  padding: 16px;
 }
 
-.rejectBtn {
-  background: #ff4d4f;
-  color: #fff;
+:global(.adm-card-header) {
+  padding: 16px 16px 12px;
 }