docs(agents,dogfood): point both ablation instruction surfaces at scripts/ablation-replace.mjs beside its sibling preflight

The two documents that route an agent to `scripts/ablation-dist-preflight.mjs`
now also route it to `scripts/ablation-replace.mjs`, in the order an ablation
runs them: mutate on disk through the anchor-verifying helper, then prove the
mutation reached `dist/` with the preflight, then read the run.

`.claude/agents/os-dev.md` stays line-neutral (403 / 403): the new pointer sits
under the mutate-then-build line of the ablation step; it is paid for by
deleting the 干净收尾 opener that restated the header's two-delivery rule and the
following bullet's ordering. `packages/qa/dogfood/README.md` gains one sentence
in step 4 of "Adding a golden test", beside the existing preflight sentence.

Adoption-style pointer only: not a mandatory path, no gate, no migration of
existing ablation scripts.

Co-authored-by: Claude <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Gqi43smmqjJ5sUrhfoPeKu

Author: claude

.claude/agents/os-dev.md

@@ -251,6 +251,7 @@ model: opus
 - 那份绿给一条可能永远失败不了的断言背书,对 CI 永久隐形(CI 构建正确,那边永远绿)。
 - 消融本就为证明新门禁能失败时,这份假绿读作门禁没触发,于是有人去弱化一条好门禁。
 - 每一腿(变异与还原)都是:改动 → 证明它真落到了磁盘 → `pnpm --filter <pkg> build`。
+- 落盘走 `node scripts/ablation-replace.mjs`,不走 `-i` 家族:锚点必须命中,写入与还原按磁盘核验。
 - 再证明它到达了 `dist/`,才读运行结果:`node scripts/ablation-dist-preflight.mjs <pkg> '<marker>'`。
 - 删守卫的消融以及每个还原腿,用 `--absent`。
 - ⛔ 还原腿不可跳过:留在 `dist/` 里的 marker 会让变异代码对该树之后的每次运行继续生效。
@@ -316,7 +317,6 @@ model: opus
 
 ## 干净收尾 —— 报告是你的终局动作
 
-- 报告落两次,GitHub 优先:卡片评论在前,终报消息在后。
 - 终报消息之前,把同一段 JSON 发成 issue 评论,首行单独一行、就是字面纯文本 `os-dev-report`。
 - 全文 ⛔ 不出现 HTML 注释:sanitizer 落库后吃短尖括号片段,连反引号里的也吃。
 - 被吃掉标记的评论对 PM 扫描不可见;HTML 注释形不是等价写法,是坏写法。

packages/qa/dogfood/README.md

@@ -46,7 +46,11 @@ the generic verifier cannot auto-derive.
    green-on-the-bug test is not a gate — and an ablation run against a stale `dist/`
    is exactly that, silently: it certifies an assertion that may never be able to
    fail, and no later CI run can expose it (CI builds correctly, so it stays green
-   there forever). Prove the mutation actually reached the built artifact before
+   there forever). Make the revert itself through
+   `node scripts/ablation-replace.mjs --file <path> --anchor <text> --replacement <text> -- <cmd>`
+   rather than `sed -i` / `perl -i`: the anchor must hit, the write and the restore are
+   verified against the disk, and a mutation that did not land exits non-zero instead of
+   handing you a green run. Prove the mutation actually reached the built artifact before
    trusting the colour: `node scripts/ablation-dist-preflight.mjs <pkg> '<marker>'`
    (`--absent` when the revert deletes a guard rather than adding something
    identifiable) exits non-zero unless it does.