fix: 市场情绪页空态提示层铺满全页拦截鼠标

资金日历的 .fund-card 未设置 position:relative，其空态提示
.empty-hint（absolute + inset:0）向上找到了无定位祖先，直接以
初始包含块铺满整个视口，把全页链接/按钮都挡住。修复：

- .fund-card 加 position:relative，提示层收回卡片内
- .empty-hint 加 pointer-events:none，纯信息层双保险永不拦截交互

web-ui/src/views/SentimentView.vue

@@ -642,6 +642,7 @@ onBeforeUnmount(() => {
   opacity: 0.6;
 }
 .fund-card {
+  position: relative;
   display: flex;
   flex-direction: column;
   gap: 6px;
@@ -682,6 +683,7 @@ onBeforeUnmount(() => {
 .empty-hint {
   position: absolute;
   inset: 0;
+  pointer-events: none;
   display: flex;
   align-items: center;
   justify-content: center;