chore(清理): 删掉并行试跑、搬库、Python3 别名、旧链接这些过渡期的兼容写法

- 部署：JUDGE_STATE_DIR 不再强制设；删掉搬库脚本和只为搬库存在的自检、提醒
- 语言：Python3 / Python2 别名表删掉，normalizeLanguage 改名 parseLanguage
- 旧链接：后台题单详情的跳转、用户列表 -last_login 的转换
- 旧页面：布置作业必须带 language（null = 没选）；不再清旧版出题页草稿

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

apps/api/src/routes/classroom.ts

@@ -733,8 +733,7 @@ classroomRoutes.put('/classroom/lesson', requireTeacher, async (c) => {
   const parsed = await parseBody(c, classLessonRequestSchema, '题号或语言不对')
   if (!parsed.success) return parsed.response
   const user = c.get('user')!
-  const { className, problemDisplayIds } = parsed.data
-  const language = parsed.data.language ?? null
+  const { className, problemDisplayIds, language } = parsed.data
   const day = calendarDay()
 
   const [exists] = await db.select({ id: schema.user.id }).from(schema.user).where(eq(schema.user.className, className)).limit(1)