From 047e48bd8dd89ef3afadd39467ae0726e4fbe3b7 Mon Sep 17 00:00:00 2001
From: Tianyi Cui <53024+tianyicui@users.noreply.github.com>
Date: Sun, 26 Jul 2026 21:59:03 +0800
Subject: [PATCH] docs: preserve incremental PR retarget checkpoints

---
 ...-incremental-pr-base-retargeting.i18n.yaml |  6 +++++
 ...6-07-26-incremental-pr-base-retargeting.md | 27 +++++++++++++++++++
 ...7-26-incremental-pr-base-retargeting.zh.md | 27 +++++++++++++++++++
 .../skills/dsh-merging-stacked-prs/SKILL.md   |  1 +
 AGENTS.md                                     |  4 +--
 5 files changed, 63 insertions(+), 2 deletions(-)
 create mode 100644 .agents/notes/implemented/process/2026-07-26-incremental-pr-base-retargeting.i18n.yaml
 create mode 100644 .agents/notes/implemented/process/2026-07-26-incremental-pr-base-retargeting.md
 create mode 100644 .agents/notes/implemented/process/2026-07-26-incremental-pr-base-retargeting.zh.md

diff --git a/.agents/notes/implemented/process/2026-07-26-incremental-pr-base-retargeting.i18n.yaml b/.agents/notes/implemented/process/2026-07-26-incremental-pr-base-retargeting.i18n.yaml
new file mode 100644
index 0000000000..2e9a5d6402
--- /dev/null
+++ b/.agents/notes/implemented/process/2026-07-26-incremental-pr-base-retargeting.i18n.yaml
@@ -0,0 +1,6 @@
+# Bilingual-pair consistency record (docs/i18n/README.md): the git blob hash of each
+# 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
+2026-07-26-incremental-pr-base-retargeting.md: e2097ac4c32a926c8c0271df19dbc9796d0ed19d
+2026-07-26-incremental-pr-base-retargeting.zh.md: a6c94b66732b6c037fee1b0726b31ecb6f3b48c5
diff --git a/.agents/notes/implemented/process/2026-07-26-incremental-pr-base-retargeting.md b/.agents/notes/implemented/process/2026-07-26-incremental-pr-base-retargeting.md
new file mode 100644
index 0000000000..e2097ac4c3
--- /dev/null
+++ b/.agents/notes/implemented/process/2026-07-26-incremental-pr-base-retargeting.md
@@ -0,0 +1,27 @@
+# Agent Note: Retarget PR bases incrementally
+
+Status: implemented
+
+English | [中文](2026-07-26-incremental-pr-base-retargeting.zh.md)
+
+## Problem
+
+A PR base can advance while its current tip is being merged into the PR branch. Restarting from the newer tip discards completed conflict resolution and validation. Rewriting a merge that is already pushed also erases reviewable history.
+
+## Decision
+
+Each observed base tip gets its own merge checkpoint. If the base advances during the work, finish and validate the merge already in progress, commit it, and push it when the task authorizes a push. Only then fetch and merge the newer base in a separate merge commit. Never abandon, amend, rebase, or otherwise rewrite the earlier work.
+
+The root [AGENTS.md](../../../../AGENTS.md) states the standing order. The [stacked-PR landing skill](../../../skills/dsh-merging-stacked-prs/SKILL.md) applies it while retargeting dependent PRs, and the [stack review guide](../../../../docs/cookbook/responding-to-pr-review-on-a-stack.md) owns merging fixes down a stack.
+
+## Alternatives considered
+
+**Abort and restart from the newest base.** This discards resolved conflicts and completed validation, repeats work, and removes a useful recovery point.
+
+**Fold both base tips into one rewritten merge.** This hides the order in which conflicts were resolved and requires rewriting remote history if the first merge was pushed.
+
+## Consequences
+
+- A PR can carry several base-merge commits when its base advances repeatedly.
+- Completed work remains reviewable and recoverable instead of being discarded.
+- Merging a newer base changes the combined tree, so the relevant checks run again before the next push.
diff --git a/.agents/notes/implemented/process/2026-07-26-incremental-pr-base-retargeting.zh.md b/.agents/notes/implemented/process/2026-07-26-incremental-pr-base-retargeting.zh.md
new file mode 100644
index 0000000000..a6c94b6673
--- /dev/null
+++ b/.agents/notes/implemented/process/2026-07-26-incremental-pr-base-retargeting.zh.md
@@ -0,0 +1,27 @@
+# Agent Note: 增量更新 PR 的 base 分支
+
+Status: implemented
+
+[English](2026-07-26-incremental-pr-base-retargeting.md) | 中文
+
+## 问题
+
+将 PR（Pull Request）的 base 分支当前顶端提交合入 PR 分支的过程中，base 分支可能继续前移。若改从新的顶端提交重新开始，就会丢弃已经完成的冲突解决和验证工作。重写已经推送的合并还会抹去可供评审的历史记录。
+
+## 决策
+
+每次观察到的 base 分支顶端提交都保留为独立的合并检查点。如果处理期间 base 分支继续前移，先完成并验证正在进行的合并，再将其提交；任务授权推送时，还要完成推送。完成这些步骤后，才能拉取较新的 base，并通过单独的合并提交将其合入。绝不放弃先前工作，也不通过 amend、rebase 或其他方式重写它。
+
+根 [AGENTS.md](../../../../AGENTS.md) 规定了这项常设指令。[堆叠 PR 落地 skill（技能）](../../../skills/dsh-merging-stacked-prs/SKILL.md)在调整依赖 PR 的 base 时执行这一规则，[堆叠评审指南](../../../../docs/cookbook/responding-to-pr-review-on-a-stack.md)则负责说明如何将修复沿堆叠向下合并。
+
+## 曾考虑的替代方案
+
+**中止当前工作，改从最新 base 重新开始。** 这会丢弃已经解决的冲突和完成的验证，重复劳动，并失去一个有用的恢复点。
+
+**重写为一次同时包含两个 base 分支顶端的合并。** 这会掩盖冲突解决的顺序；如果第一次合并已经推送，还必须重写远程历史。
+
+## 后果
+
+- PR 的 base 多次前移时，这个 PR 可以包含多个用于合并 base 的提交。
+- 已完成的工作不会被丢弃，而是保持可供评审和恢复。
+- 合入较新的 base 会改变合并后的文件树，因此相关检查会在下一次推送前重新运行。
diff --git a/.agents/skills/dsh-merging-stacked-prs/SKILL.md b/.agents/skills/dsh-merging-stacked-prs/SKILL.md
index dc1d2ec265..50ceda2233 100644
--- a/.agents/skills/dsh-merging-stacked-prs/SKILL.md
+++ b/.agents/skills/dsh-merging-stacked-prs/SKILL.md
@@ -20,6 +20,7 @@ Given `A ← B ← C` landing on `master`:
 2. **Retarget PR B, refresh it, then merge it — keeping its branch.**
    - `gh pr edit B --base master` (now that A is in master, B's base becomes master).
    - Merge the new master *into* branch B: check out B, `git fetch origin`, `git merge origin/master` — merge `origin/master`, not local `master`, because `gh pr merge` updated only GitHub and the local branch is stale — resolve any conflicts here, and push. This makes B current and surfaces conflicts in the working branch where they can be tested — not as a surprise at the GitHub merge.
+   - If `origin/master` moves during that work, finish and push the in-progress merge, then fetch and merge the newer tip in a separate commit. Never abandon or rewrite the earlier work ([rationale](../../notes/implemented/process/2026-07-26-incremental-pr-base-retargeting.md)).
    - `gh pr merge B --merge` — still no `--delete-branch` (PR C bases on branch B).
 
 3. **Retarget PR C, refresh it, then merge it — keeping its branch.** Same steps: `gh pr edit C --base master`, fetch and merge `origin/master` into branch C, resolve conflicts there and push, then `gh pr merge C --merge` without `--delete-branch`.
diff --git a/AGENTS.md b/AGENTS.md
index a8f811229a..943265723a 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -111,8 +111,8 @@ Real-API tests and demos read `DEEPSEEK_API_KEY`, optional `DEEPSEEK_BASE_URL`,
 - **Testing policy** — [docs/testing.md](docs/testing.md). Every non-trivial model- or product-user-visible behavior change adds or updates a keyless snapshot through a real runnable example in the same PR; package tests, e2e-only assertions, and mock-only fixtures do not substitute for the assembled application transcript. Fixtures must replay on macOS/Linux; fix fixtures, not normalizers.
 - **A tool's UI render intent is part of its design**, decided up front (`generic`/`terminal`/`diff`, `locations`); presentation methods are pure functions of `args` ([cookbook](docs/cookbook/adding-a-tool.md)).
 - **Plan unit, e2e, and snapshot coverage** for new seams, lifecycle shapes, and transcript surfaces; missing snapshot-harness support is part of the implementation, not deferred follow-up.
-- **Keep PRs coherent; use merge commits.** Split independent features or design decisions when combining them obscures ownership, intent, or verification. Never squash, rebase, or rewrite pushed branches; fix the introducing PR, then merge down its stack ([guide](docs/cookbook/responding-to-pr-review-on-a-stack.md)).
-- **Label PRs:** exactly one kind (`feature`/`bug-fix`/`doc`/`testing`/`cleanup`), all matching areas; the [taxonomy](.agents/notes/implemented/process/2026-07-25-semantic-pr-label-taxonomy.md) remains extensible for recurring distinctions.
+- **Use incremental merge commits.** Split independent changes; never squash, rebase, or rewrite pushed history. Fix the introducing PR before merging down-stack. If the base advances mid-merge, never restart: finish the checkpoint, push when authorized, then merge the newer tip separately ([rationale](.agents/notes/implemented/process/2026-07-26-incremental-pr-base-retargeting.md)).
+- **Label PRs:** one kind (`feature`/`bug-fix`/`doc`/`testing`/`cleanup`), each matching area; the [taxonomy](.agents/notes/implemented/process/2026-07-25-semantic-pr-label-taxonomy.md) is extensible.
 - TODO markers: `FIXME`/`TODO`/`XXX` by urgency ([semantics](docs/development.md)).
 - Files end with exactly one trailing newline; `git diff --cached --check` (pre-commit) gates it.