feat(排名): 排名页重做成领奖台加全班赛道，一眼看出自己第几、该追谁、谁在追自己

- 一张榜两个开关：本班 / 本年级 / 全服 × 这周 / 这学期 / 全部，默认本班 · 这学期。
  原来最大那张全服 Top100 里，这学期在用的 25 级学生一个都进不去
- 做对一样多的不再按「提交少的在前」排，改成先做到的在前；名次旁边写比周一升降了几名
- 「你」那张卡：第几名、再做对几道上领奖台，要追的人早你几秒、追你的人晚你几秒
- 本年级 / 全服只列前面一段和你附近一段，中间折起来，点开再看
- 班级对抗按人均做对比，另有我和对手的名次走势、这周本班、每周冠军
- 老师不上榜，选班看；每行「⋯」能把怀疑抄代码的学生设成不计入排名（新增 user.rank_hidden_at，
  首页周榜同样不算他），随时能恢复
- 去掉全服 Top10、日活两张图、在线人数和班级详情弹框里的统计词，以及它们背后的旧接口

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

apps/web/src/oj/rank/components/RankPodium.vue

@@ -0,0 +1,188 @@
+<script setup lang="ts">
+import type { RankRow } from "@oj2/contract"
+import { useThemeVars } from "naive-ui"
+import UserName from "shared/components/UserName.vue"
+import { useRankPalette } from "../palette"
+import RankAvatar from "./RankAvatar.vue"
+
+/**
+ * 领奖台：前三名站在台阶上，第一名戴皇冠。赛道从第 4 名接着排，前三不再出现第二遍。
+ * 你要追的人站在台上时台阶描蓝边、挂「你要追的」，和赛道里的蓝条是一回事。
+ */
+const props = defineProps<{
+  rows: RankRow[]
+  meId?: number
+  chaseId?: number
+  threatId?: number
+}>()
+defineEmits<{ open: [username: string] }>()
+
+const theme = useThemeVars()
+const palette = useRankPalette()
+
+/** 台阶从左到右是 2、1、3 */
+const steps = computed(() =>
+  [2, 1, 3]
+    .map((place) => ({ place, row: props.rows[place - 1] }))
+    .filter((step): step is { place: number; row: RankRow } => !!step.row),
+)
+
+const HEIGHTS: Record<number, number> = { 1: 50, 2: 38, 3: 30 }
+</script>
+
+<template>
+  <div class="podium">
+    <div v-for="{ place, row } in steps" :key="place" class="step" :class="`p${place}`">
+      <div class="top">
+        <svg
+          v-if="place === 1"
+          class="crown"
+          width="18"
+          height="18"
+          viewBox="0 0 24 24"
+          fill="#f2c94c"
+          stroke="#9a6700"
+          stroke-width="1.6"
+          stroke-linejoin="round"
+          role="img"
+          aria-label="第一名"
+        >
+          <path d="M3 8l4.5 4L12 5l4.5 7L21 8l-2 11H5z" />
+        </svg>
+        <span v-if="row.user.id === chaseId" class="tag chase">你要追的</span>
+        <span v-else-if="row.user.id === threatId" class="tag threat">在追你</span>
+        <span v-else-if="row.user.id === meId" class="tag me">你</span>
+      </div>
+      <RankAvatar
+        :username="row.user.username"
+        :avatar="row.avatar"
+        :size="place === 1 ? 34 : 28"
+        :me="row.user.id === meId"
+      />
+      <button class="name" @click="$emit('open', row.user.username)">
+        <UserName :username="row.user.username" />
+      </button>
+      <div
+        class="block"
+        :style="{
+          height: `${HEIGHTS[place]}px`,
+          background: palette.medal[place - 1]!.background,
+          boxShadow:
+            row.user.id === chaseId
+              ? `inset 0 0 0 2px ${palette.chase}`
+              : row.user.id === meId
+                ? `inset 0 0 0 2px ${palette.me}`
+                : undefined,
+        }"
+      >
+        <span class="place" :style="{ color: palette.medal[place - 1]!.color }">{{ place }}</span>
+        <span class="solved"
+          ><b>{{ row.solved }}</b
+          ><small>道</small></span
+        >
+      </div>
+    </div>
+    <span v-if="!steps.length" class="empty">还没有人做对，现在做对 1 道就是第一名</span>
+  </div>
+</template>
+
+<style scoped>
+.podium {
+  display: flex;
+  align-items: flex-end;
+  justify-content: center;
+  gap: 6px;
+  margin: 0 16px;
+  border-bottom: 2px solid v-bind("theme.dividerColor");
+  min-height: 60px;
+}
+
+.step {
+  width: 170px;
+  min-width: 0;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  gap: 3px;
+}
+
+.top {
+  height: 18px;
+  display: flex;
+  align-items: center;
+  gap: 4px;
+}
+
+.tag {
+  font-size: 11px;
+  font-weight: 600;
+  border-radius: 3px;
+  padding: 0 5px;
+  line-height: 16px;
+  white-space: nowrap;
+}
+
+.tag.chase {
+  color: v-bind("palette.chase");
+  background: rgba(47, 111, 208, 0.12);
+}
+
+.tag.threat {
+  color: v-bind("palette.threat");
+  background: rgba(199, 106, 18, 0.12);
+}
+
+.tag.me {
+  color: v-bind("palette.me");
+  background: rgba(24, 160, 88, 0.12);
+}
+
+.name {
+  max-width: 100%;
+  padding: 0;
+  border: 0;
+  background: none;
+  font: inherit;
+  font-size: 13px;
+  cursor: pointer;
+  display: flex;
+  min-width: 0;
+}
+
+.block {
+  width: 100%;
+  box-sizing: border-box;
+  border-radius: 6px 6px 0 0;
+  display: flex;
+  align-items: flex-start;
+  justify-content: center;
+  gap: 10px;
+  padding-top: 5px;
+}
+
+.place {
+  font-size: 22px;
+  font-weight: 800;
+  line-height: 1;
+}
+
+.solved {
+  font-variant-numeric: tabular-nums;
+}
+
+.solved b {
+  font-size: 16px;
+}
+
+.solved small {
+  font-size: 11px;
+  color: v-bind("theme.textColor3");
+  margin-left: 1px;
+}
+
+.empty {
+  padding: 18px 0;
+  color: v-bind("theme.textColor3");
+  font-size: 13px;
+}
+</style>