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/contest/list.vue

@@ -1,15 +1,15 @@
 <script setup lang="ts">
 import { NSwitch, NTag } from "naive-ui"
 import ContestTitle from "shared/components/ContestTitle.vue"
-import ContestType from "shared/components/ContestType.vue"
+import ContestAccessTag from "shared/components/ContestAccessTag.vue"
 import Pagination from "shared/components/Pagination.vue"
 import { CONTEST_STATUS } from "utils/constants"
 import { parseTime } from "utils/functions"
-import type { Contest } from "utils/types"
+import type { AdminContest } from "utils/types"
 import { editContest, getContestList } from "../api"
 import Actions from "./components/Actions.vue"
 
-const contests = ref<Contest[]>([])
+const contests = ref<AdminContest[]>([])
 const total = ref(0)
 const query = reactive({
   limit: 10,
@@ -17,12 +17,12 @@ const query = reactive({
   keyword: "",
 })
 
-function toggleVisible(contest: Contest) {
+function toggleVisible(contest: AdminContest) {
   contest.visible = !contest.visible
   editContest(contest)
 }
 
-const columns: DataTableColumn<Contest>[] = [
+const columns: DataTableColumn<AdminContest>[] = [
   { title: "ID", key: "id", width: 60 },
   {
     title: "比赛",
@@ -39,7 +39,7 @@ const columns: DataTableColumn<Contest>[] = [
     title: "类型",
     key: "contest_type",
     width: 100,
-    render: (row) => h(ContestType, { contest: row, size: "small" }),
+    render: (row) => h(ContestAccessTag, { contest: row, size: "small" }),
   },
   {
     title: "状态",