feat(题目): 判题结果从提交按钮下的浮层挪到左栏「结果」页签——改代码时结果就摆在旁边

原来结果是提交按钮下面的 n-popover：点一下外面就收起、最高 600px、盖住编辑器，
学生没法一边看「正确输出 / 你的输出」一边改代码，还得靠「上次结果」按钮找回来。

- 左栏新增「结果」页签（手机上排在「代码」后面），交上去或者语法检查没过就自动切过去；
  页签标题带状态图标（✕ / ✓ / ! / 判题中转圈），不只靠颜色
- 页签用 show:lazy：切走不卸载，编辑器里的错误标记、AI 提示都留着
- 「题目描述」改叫「题目」；去掉浮层和「上次结果」按钮

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

apps/web/src/oj/problem/components/ResultTabLabel.vue

@@ -0,0 +1,60 @@
+<script setup lang="ts">
+import { Icon } from "@iconify/vue"
+import { useThemeVars } from "naive-ui"
+import { storeToRefs } from "pinia"
+import { useSubmissionStore } from "oj/store/submission"
+import { SubmissionStatus } from "utils/constants"
+
+/**
+ * 「结果」页签的标题：带上这一次的状态。用图标而不是一个彩色小圆点 ——
+ * 机房投影、色弱的学生只靠颜色分不出对错。
+ */
+
+const theme = useThemeVars()
+const { submission, syntaxErrorInfo, judging, pending, submitting } =
+  storeToRefs(useSubmissionStore())
+
+const status = computed(() => {
+  if (syntaxErrorInfo.value) return { icon: "ph:warning-bold", color: theme.value.warningColor }
+  if (!submission.value) return null
+  if (judging.value || pending.value || submitting.value)
+    return { icon: "ph:circle-notch-bold", color: theme.value.infoColor, spin: true }
+  const result = submission.value.result
+  if (result === SubmissionStatus.accepted)
+    return { icon: "ph:check-bold", color: theme.value.successColor }
+  if (result === SubmissionStatus.ast_check_failed)
+    return { icon: "ph:warning-bold", color: theme.value.warningColor }
+  return { icon: "ph:x-bold", color: theme.value.errorColor }
+})
+</script>
+
+<template>
+  <span class="label">
+    结果
+    <Icon
+      v-if="status"
+      :icon="status.icon"
+      :color="status.color"
+      :class="{ spin: status.spin }"
+      width="14"
+    />
+  </span>
+</template>
+
+<style scoped>
+.label {
+  display: inline-flex;
+  align-items: center;
+  gap: 4px;
+}
+
+.spin {
+  animation: spin 1s linear infinite;
+}
+
+@keyframes spin {
+  to {
+    transform: rotate(360deg);
+  }
+}
+</style>