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/api/src/routes/helpers.ts

@@ -57,7 +57,7 @@ export function asFilterValue<T extends string | number>(
   return value as T
 }
 
-export function objectValue(value: unknown): Record<string, unknown> {
+export function asRecord(value: unknown): Record<string, unknown> {
   return value && typeof value === "object" && !Array.isArray(value)
     ? (value as Record<string, unknown>)
     : {}
@@ -96,7 +96,7 @@ export function isSuperAdmin(user: AuthUser | null | undefined) {
 
 export function publicTemplates(value: unknown) {
   const templates: Record<string, string> = {}
-  for (const [language, raw] of Object.entries(objectValue(value))) {
+  for (const [language, raw] of Object.entries(asRecord(value))) {
     if (typeof raw !== "string") continue
     const match = raw.match(/\/\/TEMPLATE BEGIN\n([\s\S]+?)\/\/TEMPLATE END/)
     templates[language] = match?.[1] ?? ""