备份策略改为部署前手动快照：部署合同增加手动快照模式 [08-28-production-arm-backup-transfer-incident]

- 用户决定仅用部署前手动轻量快照，不再推进对象存储、ARM/hyinda-20c 备份
- refresh-deployment-contract 新增 /etc/hyb-oa-backup-mode 显式模式：
  无文件保持原自动模式；manual_snapshot 要求三个备份 timer 停用且备份
  service 已退出，ops timer 仍须运行；内容/属主/符号链接异常 fail-closed
- probe 部署前与 refresh 部署后均校验模式与 timer/service 一致性
- 新增 44 backup_mode_invalid / 45 backup_timer_not_disabled 分类及合同测试
- 记录 10-05 ARM 与 hyinda-20c 只读核验结果、远端切换顺序与回滚
- 远端切换未执行，需另行批准

Co-Authored-By: Claude Opus 5.5 <[email protected]>

deploy/trialrun/validate-env-contract.js

@@ -751,6 +751,9 @@ for (const requiredFragment of [
   'refresh_program_integrity_invalid',
   'unit_build_not_refreshed',
   'timer_not_active',
+  'backup_mode_invalid',
+  'backup_timer_not_disabled',
+  'manual_snapshot',
   'systemctl daemon-reload',
 ]) {
   if (!deploymentRefreshHelperContent.includes(requiredFragment)) {