fix(比赛): 「比赛信息」里老师贴的截图不会被压扁、点一下能放大；弹框改成点开，不再鼠标一挪就收起

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/web/src/oj/contest/components/ContestInfo.vue

@@ -2,16 +2,21 @@
 import { useContestStore } from "oj/store/contest"
 import { parseTime } from "utils/functions"
 import ContestAccessTag from "shared/components/ContestAccessTag.vue"
+import Markdown from "shared/components/Markdown.vue"
 
 const contestStore = useContestStore()
 </script>
 
 <template>
-  <n-popover v-if="contestStore.contest" placement="bottom-end" :show-arrow="false">
+  <!-- 点开而不是悬停：正文里的图点开放大时，放大层盖住了弹框，悬停会当成鼠标离开把弹框连同放大层一起收掉 -->
+  <n-popover v-if="contestStore.contest" trigger="click" placement="bottom-end" :show-arrow="false">
     <template #trigger>
       <n-button>比赛信息</n-button>
     </template>
-    <div v-html="contestStore.contest.description"></div>
+    <!-- 后台富文本存的 HTML，和题面一样走 Markdown：贴进来的截图不会被压扁、点开能放大 -->
+    <div class="desc">
+      <Markdown html :content="contestStore.contest.description" />
+    </div>
     <n-descriptions bordered label-placement="left" :column="1">
       <n-descriptions-item label="开始时间">
         {{ parseTime(contestStore.contest.startTime, "YYYY年M月D日 HH:mm:ss") }}
@@ -28,3 +33,15 @@ const contestStore = useContestStore()
     </n-descriptions>
   </n-popover>
 </template>
+
+<style scoped>
+/* 截图按原宽会把弹框撑得和屏幕一样宽 */
+.desc {
+  max-width: min(480px, calc(100vw - 48px));
+  margin-bottom: 12px;
+}
+
+.desc :deep(.oj-markdown) {
+  font-size: 14px;
+}
+</style>