ci: run web replay on master linux

.agents/notes/implemented/process/2026-07-26-ci-failover-runbook.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write .agents/notes/implemented/process/2026-07-26-ci-failover-runbook.md
-2026-07-26-ci-failover-runbook.md: 4e4f8ea7fc60cf76fd8308147bbf7cc0bac74798
-2026-07-26-ci-failover-runbook.zh.md: bb7e43fe55c9cced51f042de6503978ec9349d6b
+2026-07-26-ci-failover-runbook.md: 72261f95ea74b61e3915a1a6419b2c2e616efbd9
+2026-07-26-ci-failover-runbook.zh.md: fdce40ffac5036cb4caf8eb86d20b7bb5bae4fc8

.agents/notes/implemented/process/2026-07-26-ci-failover-runbook.md

@@ -14,7 +14,7 @@ Each of the three required Linux worker jobs — and the `all checks passed` ver
 
 ### What the in-house pool is
 
-`vm-backup`: one 64-core VM, six always-on systemd-managed runner instances. Check the latest `serial / linux (self-hosted standby)` run before switching: a green standby is verified-yesterday capacity.
+`vm-backup`: one 64-core VM, six always-on systemd-managed runner instances. Its image must preinstall Playwright Chromium's Linux system packages; CI downloads the lockfile-selected browser but never runs `apt` on this persistent shared host. Check the latest `serial / linux (self-hosted standby)` run before switching: its aggregate includes browser replay, so a green standby verifies both ordinary capacity and this browser prerequisite.
 
 ### Switch (any repository writer, ~1 minute, no merge)
 

.agents/notes/implemented/process/2026-07-26-ci-failover-runbook.zh.md

@@ -14,7 +14,7 @@ Status: implemented
 
 ### 自有池是什么
 
-`vm-backup`：一台 64 核虚拟机，6 个常驻 systemd 管理的运行器实例。切换前先看 `serial / linux (self-hosted standby)` 最近一次运行：绿色 = 这套环境昨天刚被全量验证过。
+`vm-backup`：一台 64 核虚拟机，6 个常驻 systemd 管理的运行器实例。其镜像必须预装 Playwright Chromium 的 Linux 系统软件包；CI 会下载锁文件选定的浏览器，但绝不在这台持久化共享主机上运行 `apt`。切换前先看 `serial / linux (self-hosted standby)` 最近一次运行：其聚合流程包含浏览器回放，因此绿色热备同时验证常规容量和这项浏览器先决条件。
 
 ### 切换步骤（任何具备写权限的协作者，约 1 分钟，无需合并）