feat: 增强差旅报销审核流程与票据智能推理

优化本体解析和编排器的差旅场景处理能力，完善报销单草稿
保存和费用明细同步逻辑，前端报销创建页面增加行程推理和
票据审核交互，新增助手会话快照工具函数，补充单元测试。

web/src/assets/styles/views/travel-request-detail-view.css

@@ -1586,6 +1586,11 @@
   background: #fffcf7;
 }
 
+.validation-section--risk .risk-advice-card.low {
+  border-color: #dbeafe;
+  background: #f8fbff;
+}
+
 .validation-section--risk .risk-advice-card-head {
   display: flex;
   align-items: center;
@@ -1611,6 +1616,11 @@
   color: #c2410c;
 }
 
+.validation-section--risk .risk-advice-card.low .risk-advice-card-head span {
+  background: #eff6ff;
+  color: #2563eb;
+}
+
 .validation-section--risk .risk-advice-card-head strong {
   min-width: 0;
   color: #0f172a;
@@ -1660,6 +1670,11 @@
   background: #fffaf2;
 }
 
+.risk-advice-card.low {
+  border-color: #bfdbfe;
+  background: #f8fbff;
+}
+
 .risk-advice-card-head {
   display: flex;
   align-items: center;
@@ -1685,6 +1700,11 @@
   color: #c2410c;
 }
 
+.risk-advice-card.low .risk-advice-card-head span {
+  background: #dbeafe;
+  color: #2563eb;
+}
+
 .risk-advice-card-head strong {
   min-width: 0;
   color: #0f172a;