Merge pull request #1091 from deepseek-harness/feature/installer-adopt-checkout

feat(install): adopt an existing checkout into the managed layout

.agents/notes/implemented/process/2026-07-31-installer-adopts-existing-checkout.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 .agents/notes/implemented/process/2026-07-31-installer-adopts-existing-checkout.md
+2026-07-31-installer-adopts-existing-checkout.md: de3cd052f94a0d5256c7687e9a1a38ee69fd2caf
+2026-07-31-installer-adopts-existing-checkout.zh.md: 2e8be804b4af6151e77e36f8b109616aab3a18e9

.agents/notes/implemented/process/2026-07-31-installer-adopts-existing-checkout.md

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+# Agent Note: the installer adopts an existing checkout into the managed layout
+
+Status: implemented
+
+English | [中文](2026-07-31-installer-adopts-existing-checkout.zh.md)
+
+## Problem
+
+`scripts/install.sh` produced two incompatible install shapes. A `curl … | sh` install built the managed layout — a master clone at `~/.dsh/source/master`, a staging worktree on `dsh-staging/<timestamp>`, and the stable `current` symlink the PATH launcher resolves through. Running the same script from a checkout instead linked `dsh` straight at that checkout's `bin/dsh`, per the earlier [in-repo skip-clone decision](../../archived/process/2026-07-22-installer-in-repo-skip-clone.md).
+
+The direct link is a terminal state. `current` is what an upgrade repoints, so an install without it is not upgradable by [`dsh-upgrade`](../../../../skills/dsh-upgrade/SKILL.md); the PATH symlink dangles if the checkout moves; and the launcher resolves to whatever branch the contributor happened to have checked out, which the upgrade contract forbids as a launcher target. The upgrade skill already described this shape as a legacy install needing a one-time migration, so the layouts diverged at install time and were reconciled only later, if ever.
+
+## Decision
+
+In-repo mode still never clones and never modifies the working tree, but it now **adopts** the checkout into the managed layout unconditionally. There is no opt-out: one layout serves every install.
+
+The container owns staging worktrees and `current`; the repository is *discovered*, not owned. `git rev-parse --git-common-dir` resolves the shared git directory behind the checkout — for a linked worktree that is the real clone rather than the worktree itself — and its parent is the repository that serves as the upgrade base. A staging worktree branched from the checkout's `HEAD` is then created under `$DSH_SOURCE`, and `current` points at it. A clone anywhere on disk therefore converges on the same layout as a `curl` install, and the two paths share one worktree/exclude/lock/link sequence: they differ only in whether the repository was discovered by `git clone` or by `git rev-parse`.
+
+The installer records nothing about where that repository lives. A container whose repository sits outside it is not self-contained — each staging worktree holds an absolute gitdir pointer into that clone, so deleting the clone breaks them — but git already owns that fact: the worktree's `.git` file names the path, and `git worktree list` in the clone enumerates every worktree depending on it.
+
+Adoption branches from `HEAD`, so committed work is what runs and uncommitted changes stay in the checkout. This is not prompted or warned about: the installer builds the layout and gets out of the way. Setting `DSH_SOURCE` to a different directory remains the one documented way to opt back into cloning a separate tree.
+
+Every path comparison runs on physical paths through a `resolve_dir` helper, and every compared value is resolved at assignment rather than at the comparison. Git always reports resolved paths, so comparing one against an unresolved path disagrees whenever a symlink sits anywhere above the checkout — a symlinked home directory is enough, and macOS reaches every `mktemp` path that way through `/var` -> `private/var`. The mismatch misclassified an existing managed install as a foreign clone and would have built a second container beside the real one. The same defect recurred twice more during review, both times as one side of a comparison left unresolved: a curl install's `REPO_ROOT`, and the container path it was compared against. `resolve_dir` therefore echoes a missing path back rather than failing, so a not-yet-created container needs no per-call fallback and no site can compare against an empty path by forgetting one; callers that need "does not exist" test the directory explicitly. `git rev-parse --path-format=absolute` would do the same job but requires git 2.31+.
+
+Before `current` is repointed, the installer rejects a staging path that resolves to the repository itself, enforcing the upgrade contract that the launcher never resolves to the master clone.
+
+## Alternatives considered
+
+**Make `~/.dsh/source/master` a symlink to the arbitrary clone.** Rejected. Git resolves the symlink and records the *real* path: a worktree created through it stores `gitdir: …/<clone>/.git/worktrees/<name>`, and `git worktree list` reports the clone. The symlink is therefore decorative — nothing reads it — while implying the container owns the repository. It also fails silently: moving the clone leaves `master` present but dangling and every staging worktree dead with `fatal: not a git repository`. Worst, it aliases two names onto one tree, so the "current must never be the master clone" check passes by string comparison while being false. `~/.dsh/source/master` is a location, not a name, and only the location is authoritative.
+
+**Promote the checkout itself to the `current` target.** Rejected: the upgrade contract requires `current` to be a clean staging worktree on a staging branch, never a feature, review, or detached checkout. It would also make every upgrade rewrite the tree the contributor is editing.
+
+**Keep link-in-place behind a prompt or a `DSH_ADOPT` flag.** Rejected, and an earlier revision of this change shipped exactly that before it was removed. The divergent shape was the defect itself, so retaining it as an option preserves the problem and doubles the states every later change must reason about — the prompt, the flag, the dirty-tree warning, and a second linking path all existed only to keep a shape nothing should produce. The original motivation for link-in-place, keeping the script testable against local source, survives adoption: a staging worktree branched from the checkout's `HEAD` runs the same code. `DSH_SOURCE` remains the escape hatch for installing a separate tree.
+
+**Warn or prompt when the tree is dirty.** Rejected: `worktree add` from `HEAD` cannot carry uncommitted work, so the behavior is determined and a prompt only adds a decision the user cannot act on differently. The contract is documented instead.
+
+**Put an adopted clone's staging worktrees beside the clone** (`~/src/staging-*`) rather than in `~/.dsh/source`. Rejected: `current` and the PATH launcher are per-user singletons, so scattering worktrees across clone parents reintroduces the sibling-clone sprawl the source container exists to prevent.
+
+## Consequences
+
+One layout now serves every install, so an adopted clone is upgradable by `dsh-upgrade` without the one-time migration that skill described, and the installer has no branch that produces an unupgradable shape. In-repo runs still never mutate the working tree.
+
+The cost is that a contributor can no longer point PATH at a checkout and have `dsh` follow that working tree as they switch branches: the launcher now resolves to a staging worktree pinned to the `HEAD` adopted at install time. Re-running the installer adopts the current `HEAD` again.
+
+A container adopting an outside clone is also no longer self-contained: deleting that clone breaks its staging worktrees. This is inherent to reusing an existing clone rather than a property of this design — the rejected symlink hides it rather than fixing it — and git's own worktree records are what diagnose it.
+
+## Testing
+
+`scripts/install.sh` has no automated test, and this change does not add one: the user directed that `install.spec.ts` be left out of scope. That is a known gap on a shipped user-facing path, and the `/var` resolution defect above is exactly the class of bug a test would have caught first. The standing [`FIXME(install-ts)`](../../../../scripts/install.sh) asking for this workflow to move into a tested TypeScript entrypoint is correspondingly more pressing.
+
+Verification was manual, through a throwaway harness driving the real script with a stubbed `pnpm`: adopting a standalone clone; adopting from a linked worktree into its existing container; an explicit `DSH_SOURCE` still opting back into cloning; a dirty tree adopting silently with no prompt or warning while its uncommitted file stays behind; a non-git checkout failing with guidance; and a `curl`-style clone install asserting the built layout, which is the regression that caught the unresolved-`REPO_ROOT` defect. The interactive path was exercised under tmux from a dirty checkout, confirming the run reaches the launcher with no adoption prompt and ends with `dsh` running from the new staging worktree while the original checkout keeps its branch and its uncommitted file.

.agents/notes/implemented/process/2026-07-31-installer-adopts-existing-checkout.zh.md

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+# Agent Note: 安装器把已有检出接管进受管布局
+
+Status: implemented
+
+[English](2026-07-31-installer-adopts-existing-checkout.md) | 中文
+
+## Problem
+
+`scripts/install.sh`会产生两种互不兼容的安装形态。`curl … | sh`安装会构建受管布局——`~/.dsh/source/master`处的 master 克隆、位于`dsh-staging/<时间戳>`分支上的 staging worktree，以及 PATH 启动器据以解析的稳定`current`符号链接。而从检出中运行同一脚本时，则依据此前的[检出内跳过克隆决策](../../archived/process/2026-07-22-installer-in-repo-skip-clone.md)，把`dsh`直接链接到该检出的`bin/dsh`。
+
+这种直接链接是一种终态。升级重指的正是`current`，因此缺少它的安装无法通过[`dsh-upgrade`](../../../../skills/dsh-upgrade/SKILL.md)升级；检出一旦移动，PATH 符号链接就会失效；而且启动器会解析到贡献者恰好检出的任意分支，这正是升级契约禁止作为启动器目标的情形。升级技能早已把这种形态描述为需要一次性迁移的旧式安装，于是两种布局在安装时就已分叉，并且要到很久以后才会被调和——甚至永远不会。
+
+## Decision
+
+检出内模式仍然绝不克隆、绝不修改工作树，但现在它会无条件地把该检出**接管**进受管布局。不存在退出选项：一套布局服务于所有安装。
+
+容器拥有 staging worktree 和`current`；仓库是被*发现*的，而非被拥有的。`git rev-parse --git-common-dir`会解析出该检出背后的共享 git 目录——对于 linked worktree，那是真正的克隆而非 worktree 自身——其父目录即是充当升级基础的仓库。随后以该检出的`HEAD`为起点，在`$DSH_SOURCE`下创建 staging worktree，并让`current`指向它。因此，磁盘上任意位置的克隆都会收敛到与`curl`安装相同的布局，且两条路径共用同一套 worktree/exclude/lock/link 流程：二者的唯一差别，只在于仓库是由`git clone`发现的，还是由`git rev-parse`发现的。
+
+安装器不会记录该仓库位于何处。仓库位于容器之外时，容器就不是自包含的——每个 staging worktree 都持有指向该克隆的绝对 gitdir 指针，删除该克隆就会破坏它们——但这一事实本就由 git 自己掌握：worktree 的`.git`文件写明了该路径，而在该克隆中执行`git worktree list`会列出依赖于它的每一个 worktree。
+
+接管以`HEAD`为分支起点，因此运行的是已提交的内容，未提交的更改仍留在检出中。这一点既不提示也不警告：安装器构建好布局后便不再打扰。把`DSH_SOURCE`设为其他目录，仍是唯一有文档记载的、回到克隆另一棵树的方式。
+
+所有路径比较都通过`resolve_dir`辅助函数在物理路径上进行，且每个参与比较的值都在赋值时解析，而非在比较时解析。git 报告的始终是已解析的路径，因此只要检出之上任意一层存在符号链接，拿它与未解析的路径相比较就会不相等——家目录本身是符号链接即已足够，而 macOS 通过`/var` -> `private/var`使每个`mktemp`路径都如此。这种不匹配会把已有的受管安装误判为外来克隆，并在真正的容器旁再建一个容器。同一缺陷在评审过程中又出现了两次，两次都是比较的一侧未经解析：一次是 curl 安装的`REPO_ROOT`，一次是与之比较的容器路径。因此`resolve_dir`在路径不存在时原样回显该路径而非失败，这样尚未创建的容器无需在每个调用点单独兜底，也就没有调用点会因遗漏兜底而与空路径比较；需要判断"不存在"的调用方则显式检测该目录。`git rev-parse --path-format=absolute`能完成同样的工作，但要求 git 2.31 及以上版本。
+
+在重指`current`之前，安装器会拒绝解析结果等于仓库自身的 staging 路径，以此落实"启动器绝不解析到 master 克隆"这一升级契约。
+
+## Alternatives considered
+
+**把`~/.dsh/source/master`做成指向该任意克隆的符号链接。** 已否决。Git 会解析该符号链接并记录*真实*路径：经由它创建的 worktree 会存储`gitdir: …/<克隆>/.git/worktrees/<名称>`，而`git worktree list`报告的是该克隆。因此这个符号链接纯属装饰——没有任何代码读取它——却又暗示容器拥有该仓库。它还会静默失效：移动克隆后，`master`看似仍在却已悬空，而每个 staging worktree 都会以`fatal: not a git repository`失败。最糟的是，它把两个名称别名到同一棵树上，于是"current 绝不能是 master 克隆"这项检查会在字符串比较下通过，实则为假。`~/.dsh/source/master`是位置而非名称，且只有位置具有权威性。
+
+**把检出自身提升为`current`的目标。** 已否决：升级契约要求`current`必须是位于 staging 分支上的干净 staging worktree，绝不能是 feature、review 或 detached 检出。这还会使每次升级都改写贡献者正在编辑的那棵树。
+
+**把就地链接保留在提示或`DSH_ADOPT`开关之后。** 已否决；本次变更的早期修订版本正是如此实现，之后被移除。分叉的形态本身就是缺陷，因此把它保留为一个选项等于保留了问题，并使此后每次改动需要推敲的状态翻倍——提示、开关、工作树不干净的警告，以及第二条链接路径，全都只为维持一种本不该产生的形态而存在。就地链接最初的动机——让脚本能针对本地源码进行测试——在接管方案下依然成立：以检出的`HEAD`为起点创建的 staging worktree 运行的是同一份代码。`DSH_SOURCE`仍是安装另一棵树的退路。
+
+**在工作树不干净时发出警告或提示。** 已否决：以`HEAD`为起点的`worktree add`本就无法带上未提交的内容，因此该行为是确定的，提示只会增加一个用户无法做出不同选择的决策点。改为在文档中说明该契约。
+
+**把被接管克隆的 staging worktree 放在该克隆旁边**（`~/src/staging-*`），而非放进`~/.dsh/source`。已否决：`current`和 PATH 启动器都是每用户唯一的，因此把 worktree 散落到各个克隆的父目录中，会重新引入 source 容器本就为之而设、意在杜绝的同级克隆蔓延问题。
+
+## Consequences
+
+现在一套布局服务于所有安装，因此被接管的克隆无需该技能所述的一次性迁移，即可由`dsh-upgrade`升级，而且安装器不再有任何一条分支会产生无法升级的形态。检出内运行仍然绝不改动工作树。
+
+代价是：贡献者不能再把 PATH 指向某个检出、并让`dsh`随其切换分支而跟随该工作树；启动器现在解析到的是一个固定在安装时所接管`HEAD`上的 staging worktree。重新运行安装器会再次接管当前的`HEAD`。
+
+此外，接管外部克隆的容器不再自包含：删除该克隆会破坏其 staging worktree。这是复用已有克隆的固有属性，而非本设计带来的性质——被否决的符号链接方案只是掩盖它，而非修复它——诊断依据则是 git 自身的 worktree 记录。
+
+## Testing
+
+`scripts/install.sh`没有自动化测试，本次变更也未添加：用户明确要求把`install.spec.ts`排除在范围之外。这是一条已交付的、面向用户的安装路径上的已知缺口，而上文那个`/var`解析缺陷，恰恰属于测试本应最先捕获的那类 bug。相应地，要求把这套流程迁移到有测试覆盖的 TypeScript 入口的既有[`FIXME(install-ts)`](../../../../scripts/install.sh)也变得更为紧迫。
+
+验证是手工完成的，通过一个一次性测试装置以打桩的`pnpm`驱动真实脚本：接管独立克隆；从 linked worktree 接管进其已有容器；显式`DSH_SOURCE`仍回到克隆路径；工作树不干净时静默接管、既不提示也不警告，且其未提交文件留在原处；非 git 检出失败并给出指引；以及`curl`式克隆安装断言所构建的布局——正是这项回归测试捕获了`REPO_ROOT`未解析的缺陷。交互路径在 tmux 下从一个不干净的检出走通，确认整个过程不出现接管提示即可到达启动器，最终`dsh`从新的 staging worktree 运行，而原检出保持其分支不变、未提交文件仍在。