refactor(判题机): 换成 go-judge，空闲内存从几百 MB 降到 16 MB

原来的 JudgeServer 按核数起 gunicorn worker、每份提交再按核数开进程池，空闲内存跟着核数走
（2 核 52MB、16 核 305MB）。换成 go-judge 后空闲 16MB，同一批提交判题中 80–100MB（原来约 370MB）。

go-judge 只管在沙箱里跑命令，编译、逐点运行、比对输出、定状态码搬到 judge/sandbox.ts，
口径逐条照搬 JudgeServer，出参形状不变。拿生产库真实提交新旧逐点对比：C 2000 份 1989 一致、
C++ 891 份 890 一致、Python 2000 份全一致；不一致的是 system("pause")（现在不再判运行时错误）、
未定义行为、endl 死循环打印（运行时错误变运行超时），见 docker/judge/README.md。

- 判题容器改成 privileged（go-judge 要自己建 cgroup），镜像 oj2-judge-3
- 心跳改由 worker 每 5 秒问判题机 /version 代记，删掉 /api/judge-server/heartbeat
- 前端统一用 stripJudgePath 去掉判题机工作目录（新的 /w/ 和旧的 /judger/run/）
- 提交前编译检查只编译不运行

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

apps/web/src/oj/learn/components/CodeRunBlock.vue

@@ -3,7 +3,7 @@ import { Icon } from '@iconify/vue'
 import type { StatisticInfo, TrialRunResponse } from '@oj2/contract'
 import { errorMessage } from 'utils/api'
 import { SubmissionStatus } from 'utils/constants'
-import { trialRun } from 'utils/judge'
+import { stripJudgePath, trialRun } from 'utils/judge'
 import { explainCCompileError } from 'oj/problem/utils/cError'
 import { explainPythonCompileError } from 'utils/pythonError'
 import { explainRuntimeError } from 'oj/problem/utils/runtimeError'
@@ -63,9 +63,8 @@ const lineCount = computed(() => value.value.split('\n').length)
 
 const TOO_MUCH_OUTPUT = '程序输出太多了，一直停不下来：多半是循环没有结束的条件（条件一直成立、循环变量忘了改），在不停地打印。'
 
-/** 判题机的临时目录名对学生没有意义，只留文件名 */
 function cleanRaw(text: string) {
-  return text.replace(/\/judger\/run\/[^/"]+\//g, '').trim()
+  return stripJudgePath(text).trim()
 }
 
 function compileOutcome(raw: string): Outcome {

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

@@ -5,6 +5,7 @@ import { findChinesePunctuation } from 'oj/problem/utils/chinesePunctuation'
 import { applyFixes, clearErrorMark, currentCode, showErrorMark, showPunctuationMarks } from 'oj/problem/utils/errorMark'
 import { explainCCompileError } from 'oj/problem/utils/cError'
 import { explainPythonCompileError } from 'utils/pythonError'
+import { stripJudgePath } from 'utils/judge'
 
 /**
  * 编译错误的中文说明卡片：Python 的语法错误走 pythonError.ts，C / C++ 的 gcc 报错走
@@ -32,8 +33,7 @@ const explanation = computed(() =>
     : explainCCompileError(props.errInfo, codeStore.code.value, props.language),
 )
 
-/** 判题机的临时目录名（`/judger/run/<32 位随机串>/`）对学生没有意义，只剩文件名 */
-const rawError = computed(() => props.errInfo.replace(/\/judger\/run\/[^/"]+\//g, ''))
+const rawError = computed(() => stripJudgePath(props.errInfo))
 
 /**
  * 报错只点名第一处。别的行也有中文标点的话，一句话带过（设计稿「语法没过」：

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

@@ -4,6 +4,7 @@ import { useThemeVars } from 'naive-ui'
 import { HINT_MIN_FAILURES, hintLevelLabel, isSqlProblem } from '@oj2/contract'
 import type { JudgeCaseResult } from '@oj2/contract'
 import { JUDGE_STATUS, SubmissionStatus } from 'utils/constants'
+import { stripJudgePath } from 'utils/judge'
 import { submissionCaseResults, submissionMemoryFormat, submissionPartialCases, submissionTimeFormat } from 'utils/functions'
 import type { Submission } from 'utils/types'
 import SubmissionResultTag from 'shared/components/SubmissionResultTag.vue'
@@ -52,11 +53,6 @@ const {
   sendHintFeedback,
 } = useSubmissionStore().hint
 
-/** 判题机的临时目录名（`/judger/run/<32 位随机串>/`）对学生没有意义，只剩文件名 */
-function stripJudgePath(text: string) {
-  return text.replace(/\/judger\/run\/[^/"]+\//g, '')
-}
-
 /** 编译错误交给 CompileErrorExplain 翻成中文：Python、C、C++ 各有一张翻译表 */
 const compileError = computed(() => {
   const submission = props.submission

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

@@ -1,5 +1,6 @@
 <script setup lang="ts">
 import { SubmissionStatus } from 'utils/constants'
+import { stripJudgePath } from 'utils/judge'
 import type { StatisticInfo } from '@oj2/contract'
 import CompileErrorExplain from './CompileErrorExplain.vue'
 import RuntimeErrorExplain from './RuntimeErrorExplain.vue'
@@ -53,8 +54,7 @@ const message = computed(() => {
   }
 })
 
-/** 判题机的临时目录名（`/judger/run/<32 位随机串>/`）对学生没有意义，只剩文件名 */
-const rawOutput = computed(() => props.output.replace(/\/judger\/run\/[^/"]+\//g, ''))
+const rawOutput = computed(() => stripJudgePath(props.output))
 </script>
 
 <template>

apps/web/src/oj/submission/composables/explain.ts

@@ -1,5 +1,6 @@
 import { explainCCompileError } from 'oj/problem/utils/cError'
 import { explainPythonCompileError } from 'utils/pythonError'
+import { stripJudgePath } from 'utils/judge'
 import { explainRuntimeError } from 'oj/problem/utils/runtimeError'
 import { SubmissionStatus } from 'utils/constants'
 import type { Submission } from 'utils/types'
@@ -13,10 +14,6 @@ export interface SubmissionExplain {
   raw: string
 }
 
-function stripJudgePath(text: string) {
-  return text.replace(/\/judger\/run\/[^/"]+\//g, '')
-}
-
 /**
  * 编译失败 / 运行时错误说清楚「错在第几行、为什么」—— 翻译表和题目页结果区同一份
  * （pythonError.ts / cError.ts / runtimeError.ts）。提交列表右栏和独立的提交详情页共用。

apps/web/src/utils/judge.ts

@@ -16,3 +16,12 @@ export function trialRun(payload: TrialRunRequest) {
 export function isRunnableLanguage(language: LANGUAGE): language is RunnableLanguage {
   return language === 'C' || language === 'C++' || language === 'Python'
 }
+
+/**
+ * 报错和输出里判题机的工作目录对学生没有意义，只留文件名。两种写法：
+ * 2026-10 之前的判题机（JudgeServer）是 `/judger/run/<32 位随机串>/`，库里的老提交都是这种；
+ * 现在的 go-judge 是 `/w/`，只有 Python 会带出来（`File "/w/solution.py"`）。
+ */
+export function stripJudgePath(text: string) {
+  return text.replace(/\/judger\/run\/[^/"]+\/|\/w\/(?=solution\.py\b)/g, '')
+}