refactor: 一批名不副实的命名改掉（只动一端，不碰契约）

后端：
- getUserByToken → authenticateToken：它会删会话、续 TTL、记在线，不是纯读
- todayStart → dayStart(instant)：本来就接受任意时刻，不只是「今天」
- objectValue → asRecord，删掉 4 份一模一样的私有拷贝和 `as toObject` 别名
- 报错文案 "does not exists" / "Already be a public problem" 改通顺

前端：
- utils/types 里 Contest / User / Problem 三个别名删掉：Contest 原来指后台
  比赛、契约里同名的却是学生侧。现在 Contest = 学生侧、AdminContest = 后台，
  后台用户表单叫 AdminUserForm，题目详情直接用 ProblemDetail
- SubmissionInfo → ContestSubmissionInfo，免得和 submission.info 撞名
- utoa / atou → compressToBase64 / decompressFromBase64（实际是 zlib + base64），
  encode / decode → base64EncodeUtf8 / base64DecodeUtf8
- filterResult → toProblemRow、toProblemListItem → toAdminProblemRow，
  行字段 submission / rate → submissionCount / acRate
- 组件：Modal → AddFromLibraryModal、Form → EditorToolbar、
  ContestEditor → BasicEditor（题单也在用它）、rank 的 Index → RankMedal、
  Name → UserNameCell、Password → PasswordCell、ContestType → ContestAccessTag

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

apps/web/src/admin/problem/components/AddFromLibraryModal.vue

@@ -0,0 +1,94 @@
+<script lang="ts" setup>
+import { getProblemList } from "admin/api"
+import Pagination from "shared/components/Pagination.vue"
+import type { AdminProblemRow } from "utils/types"
+import AddButton from "./AddButton.vue"
+
+interface Props {
+  show: boolean
+  count: number
+  nextDisplayId?: string
+}
+const props = defineProps<Props>()
+const emit = defineEmits<{
+  (e: "update:show", value: boolean): void
+  (e: "change"): void
+}>()
+
+const route = useRoute()
+
+const query = reactive({
+  page: 1,
+  limit: 10,
+  keyword: "",
+})
+const total = ref(0)
+const problems = shallowRef<AdminProblemRow[]>([])
+
+const columns: DataTableColumn<AdminProblemRow>[] = [
+  { title: "编号", key: "_id", width: 80 },
+  { title: "标题", key: "title" },
+  {
+    title: "选项",
+    key: "add",
+    render: (row) =>
+      h(AddButton, {
+        problemID: row.id,
+        contestID: route.params.contestID as string,
+        nextDisplayId: props.nextDisplayId,
+        onAdded: () => emit("change"),
+      }),
+    width: 60,
+  },
+]
+
+async function getList() {
+  const offset = (query.page - 1) * query.limit
+  const res = await getProblemList(offset, query.limit, query.keyword, "", "")
+  total.value = res.total
+  problems.value = res.results
+}
+watch(
+  () => props.show,
+  (value) => {
+    if (value) getList()
+  },
+)
+watch(() => [query.limit, query.page], getList)
+watchDebounced(
+  () => query.keyword,
+  () => {
+    query.page = 1
+    getList()
+  },
+  { debounce: 500, maxWait: 1000 },
+)
+</script>
+<template>
+  <n-modal
+    :mask-closable="false"
+    :show="props.show"
+    preset="card"
+    style="width: 600px"
+    title="从题库中添加"
+    @close="$emit('update:show', false)"
+  >
+    <n-input
+      class="search"
+      v-model:value="query.keyword"
+      clearable
+      placeholder="搜索标题或编号"
+    />
+    <n-data-table striped :columns="columns" :data="problems" />
+    <Pagination
+      :total="total"
+      v-model:limit="query.limit"
+      v-model:page="query.page"
+    />
+  </n-modal>
+</template>
+<style scoped>
+.search {
+  margin-bottom: 20px;
+}
+</style>