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/utils/judge.ts

@@ -1,5 +1,5 @@
 import axios from "axios"
-import { decode, encode } from "./functions"
+import { base64DecodeUtf8, base64EncodeUtf8 } from "./functions"
 import type { Code, LANGUAGE } from "./types"
 
 const http = axios.create({ baseURL: import.meta.env.PUBLIC_JUDGE0_URL })
@@ -16,7 +16,7 @@ const JUDGE0_LANGUAGE_ID: Partial<Record<LANGUAGE, number>> = {
 }
 
 export async function createTestSubmission(code: Code, input: string) {
-  const encodedCode = encode(code.value)
+  const encodedCode = base64EncodeUtf8(code.value)
   const id = JUDGE0_LANGUAGE_ID[code.language]
   if (id === undefined) {
     return { status: null, output: `${code.language} 不支持在线试运行` }
@@ -26,7 +26,7 @@ export async function createTestSubmission(code: Code, input: string) {
   const payload = {
     source_code: encodedCode,
     language_id: id,
-    stdin: encode(input),
+    stdin: base64EncodeUtf8(input),
     redirect_stderr_to_stdout: true,
     compiler_options: compilerOptions,
   }
@@ -36,7 +36,10 @@ export async function createTestSubmission(code: Code, input: string) {
   const data = response.data
   return {
     status: data.status && data.status.id,
-    output: [decode(data.compile_output), decode(data.stdout)]
+    output: [
+      base64DecodeUtf8(data.compile_output),
+      base64DecodeUtf8(data.stdout),
+    ]
       .join("\n")
       .trim(),
   }