feat: 风险可见性控制与差旅详情页交互优化

- 新增风险可见性工具函数与风险日趋势图表组件
- 优化差旅请求详情页费用模型与视图交互
- 完善顶部导航栏样式与应用壳路由逻辑
- 补充风险可见性、风险看板与差旅详情测试覆盖

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

@@ -936,25 +936,33 @@
 .detail-expense-table .col-action { width: 9%; }
 
 .expense-time {
-  position: relative;
+  min-width: 0;
 }
 
-.expense-time.has-major-risk {
-  padding-left: 30px;
+.expense-time-content {
+  display: grid;
+  grid-template-columns: 18px minmax(0, 1fr);
+  align-items: center;
+  gap: 6px;
+  min-width: 0;
+}
+
+.expense-time-value {
+  min-width: 0;
+}
+
+.expense-risk-indicator,
+.expense-risk-indicator-placeholder {
+  width: 18px;
+  height: 18px;
 }
 
 .expense-risk-indicator {
-  position: absolute;
-  left: 8px;
-  top: 50%;
-  width: 18px;
-  height: 18px;
   padding: 0;
   border: 0;
   background: transparent;
   display: inline-grid;
   place-items: center;
-  transform: translateY(-50%);
   color: #dc2626;
   font-size: 18px;
   line-height: 1;