diff --git a/.agents/notes/implemented/process/2026-07-26-pnpm-action-setup-for-symmetric-ci-caching.i18n.yaml b/.agents/notes/implemented/process/2026-07-26-pnpm-action-setup-for-symmetric-ci-caching.i18n.yaml
new file mode 100644
index 0000000000..7ad4d7bee7
--- /dev/null
+++ b/.agents/notes/implemented/process/2026-07-26-pnpm-action-setup-for-symmetric-ci-caching.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/2026-07-26-pnpm-action-setup-for-symmetric-ci-caching.md
+2026-07-26-pnpm-action-setup-for-symmetric-ci-caching.md: 006360cedfd4d1e2c2b67ede98062a375e316f47
+2026-07-26-pnpm-action-setup-for-symmetric-ci-caching.zh.md: d511e7a2b89788fe8addd2cc47634742c7a87fe4
diff --git a/.agents/notes/implemented/process/2026-07-26-pnpm-action-setup-for-symmetric-ci-caching.md b/.agents/notes/implemented/process/2026-07-26-pnpm-action-setup-for-symmetric-ci-caching.md
new file mode 100644
index 0000000000..006360cedf
--- /dev/null
+++ b/.agents/notes/implemented/process/2026-07-26-pnpm-action-setup-for-symmetric-ci-caching.md
@@ -0,0 +1,34 @@
+# Agent Note: Provision CI pnpm via pnpm/action-setup
+
+Status: implemented
+
+English | [中文](2026-07-26-pnpm-action-setup-for-symmetric-ci-caching.zh.md)
+
+## Problem
+
+Outside `landlock-run.yml`, each workflow that installed pnpm hand-provisioned it with `corepack enable`, and five of them further repeated a hand-rolled cache setup — `pnpm store path --silent >> $GITHUB_OUTPUT`, then `actions/cache@v4` keyed on `pnpm-lock.yaml`: `e2e.yml`, `docs-pages.yml`, `pi-ai-provider-e2e.yml`, `build-exe-for-python-sdk.yml`, and the node-compat, serial-linux, and benchmark jobs of `ci.yml`. The maintained equivalent — `pnpm/action-setup@v4` (reads `packageManager` from package.json) plus `actions/setup-node` with `cache: pnpm` — was already proven in-repo in `landlock-run.yml`, and corepack's removal from newer Node distributions made every `corepack enable` a known future break.
+
+## Decision
+
+`pnpm/action-setup@v4` is the only pnpm provisioning mechanism in CI: no workflow runs `corepack enable`. The root dev dependency on `@yarnpkg/cli-dist` separately supplies the modern Yarn CLI exercised by the generated-project e2e; package-manager coverage therefore does not inherit the runner image's Yarn Classic. Caching remains per-job policy on top of pnpm provisioning, in three deliberate shapes:
+
+- **Symmetric cache** (restore and save): `actions/setup-node` with `cache: pnpm` — `e2e.yml`, `docs-pages.yml`, `pi-ai-provider-e2e.yml`, `build-exe-for-python-sdk.yml`, and the node-compat and two benchmark jobs of `ci.yml`. The larger-runner benchmark keeps its store cache Linux-only through a conditional `cache:` input; the consolidated benchmark caches on both platforms.
+- **Restore-only / producer pairing** (hand-rolled `actions/cache` steps): the three enterprise-runner PR jobs and the Wine-based pull-request Windows job restore without saving, keeping cache compression/upload off their latency-sensitive paths — an asymmetry `setup-node`'s cache cannot express. Each configures a store outside the action's replaceable install directory and resolves that path, matching the master-push serial-linux producer's path and exact key; the enterprise jobs skip restore during self-hosted failover because that VM's persistent store is already warm.
+- **Cache-less or persistent** (no store-cache action): native serial-windows and serial-macos plus `sandbox.yml` install from a cold or runner-local store. The self-hosted standby and failover jobs reuse their VM's persistent pnpm store without transferring a hosted cache archive.
+
+## Alternatives considered
+
+- **Keep the hand-rolled steps.** They worked, but they were drifting copies of setup boilerplate, and the corepack dependency was a known future break.
+- **Convert the enterprise jobs' caching to `cache: pnpm`.** Rejected: the restore-only asymmetry is a documented latency decision in `ci.yml`'s comments; erasing it to unify tooling inverts the priority.
+- **Convert serial-linux's store cache.** Rejected during implementation: the original proposal counted serial-linux among the symmetric setups, but its cache step is the producer half of the enterprise jobs' restore-only pairing — moving it to `setup-node`'s key format is the enterprise conversion by another route.
+- **Stop at the cache-bearing workflows and leave the other `corepack enable` sites.** Rejected on review follow-up: provisioning and caching are separable concerns, and leaving corepack in the cache-less jobs kept the future break and two provisioning idioms for no benefit.
+- **Rely on the runner image's Yarn.** Rejected: the hosted image exposes Yarn 1.22 after Corepack is removed, while the generated-project e2e requires Yarn 2 or newer. A locked root dev dependency makes that coverage independent of runner image contents.
+- **A composite action wrapping action-setup + setup-node.** Rejected for now: the remaining per-job variation (node-version matrices, per-platform conditional caching, the restore-only pairing) is deliberate policy, not boilerplate — a wrapper would grow mirroring inputs or flatten a real asymmetry, and the two-line pair is already near the floor.
+
+## Consequences
+
+- The corepack dependency is gone from CI entirely; pnpm arrives via the pnpm team's official action everywhere, and the version pin stays single-sourced in `package.json`'s `packageManager` field.
+- The generated-project e2e runs the root-pinned Yarn 4 CLI instead of inheriting or silently skipping the runner image's Yarn version.
+- The cache-key format changed once for converted lanes; one cold run repopulated it, after which hit rates match the old steps. The built-in key spans platform, arch, and the lockfile hash but not the Node version, so the node-compat matrix legs share one store entry — safe, because the pnpm store is Node-version-independent.
+- `setup-node`'s built-in pnpm cache restores by exact key only, with no `restore-keys` prefix fallback: a `pnpm-lock.yaml` change starts a converted lane from a cold store instead of seeding from the previous entry.
+- `pnpm/action-setup` deletes its install directory on every run and places the default store beneath the resulting `PNPM_HOME`. Linux jobs that need cache pairing or self-hosted persistence therefore set `PNPM_CONFIG_STORE_DIR` to `$HOME/.local/share/pnpm/store`, outside the action directory; the restore-only jobs and serial-linux resolve and share that stable path and exact key.
diff --git a/.agents/notes/implemented/process/2026-07-26-pnpm-action-setup-for-symmetric-ci-caching.zh.md b/.agents/notes/implemented/process/2026-07-26-pnpm-action-setup-for-symmetric-ci-caching.zh.md
new file mode 100644
index 0000000000..d511e7a2b8
--- /dev/null
+++ b/.agents/notes/implemented/process/2026-07-26-pnpm-action-setup-for-symmetric-ci-caching.zh.md
@@ -0,0 +1,34 @@
+# Agent Note: 经由 pnpm/action-setup 提供 CI 的 pnpm
+
+Status: implemented
+
+[English](2026-07-26-pnpm-action-setup-for-symmetric-ci-caching.md) | 中文
+
+## 问题
+
+除 `landlock-run.yml` 外，每个安装 pnpm 的工作流都曾用 `corepack enable` 手工提供 pnpm，其中五个还各自重复着一套手写（hand-rolled）的缓存设置——`pnpm store path --silent >> $GITHUB_OUTPUT`、再加以 `pnpm-lock.yaml` 为缓存键的 `actions/cache@v4`：`e2e.yml`、`docs-pages.yml`、`pi-ai-provider-e2e.yml`、`build-exe-for-python-sdk.yml`，以及 `ci.yml` 的 node-compat、serial-linux 与 benchmark 作业。与之等价、由官方维护的做法——`pnpm/action-setup@v4`（从 package.json 读取 `packageManager`）加带 `cache: pnpm` 的 `actions/setup-node`——当时已在仓库内的 `landlock-run.yml` 中得到验证，而 corepack 被从较新 Node 发行版中移除，使每一处 `corepack enable` 都成了已知的未来失效点。
+
+## 决策
+
+`pnpm/action-setup@v4` 是 CI 中提供 pnpm 的唯一机制：没有任何工作流运行 `corepack enable`。根目录的 `@yarnpkg/cli-dist` 开发依赖另行提供 generated-project e2e 所运行的现代 Yarn CLI（命令行界面）；因此，用于包管理器覆盖率的 Yarn 不会沿用 runner 镜像里的 Yarn Classic。缓存仍是叠加在 pnpm 提供机制上的按作业政策，保持三种刻意的形态：
+
+- **对称缓存**（既恢复也保存）：带 `cache: pnpm` 的 `actions/setup-node`——`e2e.yml`、`docs-pages.yml`、`pi-ai-provider-e2e.yml`、`build-exe-for-python-sdk.yml`，以及 `ci.yml` 的 node-compat 与两个 benchmark 作业。larger-runner benchmark 通过条件化的 `cache:` 输入让 store 缓存仅限 Linux；consolidated benchmark 在两个平台上都启用缓存。
+- **只恢复不上传／生产者配对**（手写的 `actions/cache` 步骤）：企业 runner 上的三个 PR（Pull Request）作业与基于 Wine 的拉取请求 Windows 作业只恢复不保存，把缓存压缩／上传挡在它们的延迟敏感路径之外——这种不对称是 `setup-node` 的缓存无法表达的。每个作业都在 action 可替换的安装目录之外配置 store，并解析该路径，从而与 master 推送触发的 serial-linux 生产者所用的路径和精确键匹配；企业作业在自托管故障切换期间跳过恢复，因为该 VM 的持久 store 已能直接提供热安装。
+- **无缓存或持久化**（不使用 store 缓存 action）：原生 serial-windows 和 serial-macos 加上 `sandbox.yml` 从冷 store 或 runner 本地 store 安装。自托管热备与故障切换作业复用其 VM 的持久 pnpm store，不传输托管缓存归档。
+
+## 曾考虑的替代方案
+
+- **保留手写步骤。** 它们能用，但那是会各自漂移的设置样板副本，而且对 corepack 的依赖是已知的未来失效点。
+- **把企业作业的缓存也转换成 `cache: pnpm`。** 否决：只恢复不上传的不对称是 `ci.yml` 注释中有记录的延迟决策；为统一工具而抹掉它，属于颠倒优先级。
+- **转换 serial-linux 的 store 缓存。** 实现期间否决：原提案曾把 serial-linux 计入对称设置，但其缓存步骤是企业作业只恢复不上传配对中的生产者一半——把它改成 `setup-node` 的键格式，等于换条路径做了企业作业的转换。
+- **只转换带缓存的工作流，留下其余 `corepack enable` 站点。** 评审跟进时否决：提供 pnpm 与缓存是可分离的关注点，在无缓存作业里留下 corepack 只会保留未来失效点和两套并存的提供方式，毫无收益。
+- **依赖 runner 镜像自带的 Yarn。** 否决：Corepack 移除后，托管镜像提供的是 Yarn 1.22，而 generated-project e2e 要求 Yarn 2 或更高版本。锁定版本的根开发依赖让该项覆盖率不再受 runner 镜像内容影响。
+- **用一个组合 action 包装 action-setup + setup-node。** 暂不采纳：剩余的按作业差异（node 版本矩阵、按平台的条件缓存、只恢复不上传配对）是刻意的政策而非样板——包装层要么长出镜像这些差异的输入，要么抹平一处真实的不对称，而两行的组合已接近下限。
+
+## 后果
+
+- corepack 依赖已从 CI 中彻底消失；pnpm 在所有工作流中都经由 pnpm 团队的官方 action 提供，版本锁定继续单一来源于 `package.json` 的 `packageManager` 字段。
+- generated-project e2e 运行根目录锁定的 Yarn 4 CLI，既不再沿用 runner 镜像中的 Yarn 版本，也不会因此悄然跳过。
+- 已转换泳道的缓存键格式变更了一次；各跑一次冷运行重建缓存后，命中率与旧步骤持平。内建缓存键涵盖平台、架构与锁文件哈希，但不含 Node 版本，因此 node-compat 矩阵的各条腿共享同一条 store 缓存记录——这是安全的，因为 pnpm store 与 Node 版本无关。
+- `setup-node` 内建的 pnpm 缓存只按精确键恢复，没有 `restore-keys` 前缀回退：`pnpm-lock.yaml` 一旦变更，已转换泳道会从冷 store 起步，而不是从上一条缓存记录播种。
+- `pnpm/action-setup` 每次运行都会删除其安装目录，并把默认 store 放在由此产生的 `PNPM_HOME` 下。因此，需要缓存配对或自托管持久化的 Linux 作业会把 `PNPM_CONFIG_STORE_DIR` 设为 `$HOME/.local/share/pnpm/store`，置于 action 目录之外；只恢复不上传的作业与 serial-linux 会解析并共享这一稳定路径及精确键。
diff --git a/.agents/notes/proposed/process/2026-07-26-pnpm-action-setup-for-symmetric-ci-caching.i18n.yaml b/.agents/notes/proposed/process/2026-07-26-pnpm-action-setup-for-symmetric-ci-caching.i18n.yaml
deleted file mode 100644
index 0a31f7a857..0000000000
--- a/.agents/notes/proposed/process/2026-07-26-pnpm-action-setup-for-symmetric-ci-caching.i18n.yaml
+++ /dev/null
@@ -1,6 +0,0 @@
-# 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-pnpm-action-setup-for-symmetric-ci-caching.md: 63e3f45ab2340ee2b732da286117e25be45bed08
-2026-07-26-pnpm-action-setup-for-symmetric-ci-caching.zh.md: 2348e07d58f7f0ed39a1759cc30133c8e15dbc4a
diff --git a/.agents/notes/proposed/process/2026-07-26-pnpm-action-setup-for-symmetric-ci-caching.md b/.agents/notes/proposed/process/2026-07-26-pnpm-action-setup-for-symmetric-ci-caching.md
deleted file mode 100644
index 63e3f45ab2..0000000000
--- a/.agents/notes/proposed/process/2026-07-26-pnpm-action-setup-for-symmetric-ci-caching.md
+++ /dev/null
@@ -1,31 +0,0 @@
-# Agent Note: Use pnpm/action-setup for symmetric CI pnpm caching
-
-Status: proposed
-
-English | [中文](2026-07-26-pnpm-action-setup-for-symmetric-ci-caching.zh.md)
-
-## Problem
-
-Five workflows repeat a hand-rolled three-step pnpm setup — `corepack enable`, `pnpm store path --silent >> $GITHUB_OUTPUT`, then `actions/cache@v4` keyed on `pnpm-lock.yaml`: `e2e.yml`, `docs-pages.yml`, `pi-ai-provider-e2e.yml`, `build-exe-for-python-sdk.yml`, and the node-compat, serial-linux, and benchmark jobs of `ci.yml` (~40–60 YAML lines total). The maintained equivalent — `pnpm/action-setup@v4` (reads `packageManager` from package.json) plus `actions/setup-node` with `cache: pnpm` — is already proven in-repo in `landlock-run.yml`, and also insulates against corepack's removal from newer Node distributions.
-
-## Proposal
-
-Convert the symmetric-cache workflows to `pnpm/action-setup@v4` + `setup-node` `cache: pnpm`. Explicitly do NOT convert:
-
-- the three enterprise-runner PR jobs in `ci.yml` — they deliberately use `actions/cache/restore` only, keeping cache compression/upload off the paid latency-critical path, an asymmetry `setup-node`'s cache cannot express;
-- the Windows job, which deliberately skips the store cache.
-
-## Alternatives considered
-
-- **Keep the hand-rolled steps.** They work, but they are five drifting copies of setup boilerplate, and the corepack dependency is a known future break.
-- **Convert everything including the enterprise jobs.** Rejected: the restore-only asymmetry is a documented latency decision in `ci.yml`'s comments; erasing it to unify tooling inverts the priority.
-
-## Acceptance criteria
-
-- The five symmetric workflows set up pnpm via the actions; one cold run per lane repopulates the new cache-key format, after which cache hit rates match the old steps.
-- The enterprise-runner PR jobs and the Windows job are untouched.
-
-## Risks
-
-- Cache-key format changes once (one cold run per lane).
-- A third-party action in more workflows; it is already trusted in-repo (`landlock-run.yml`) and is the pnpm team's official action.
diff --git a/.agents/notes/proposed/process/2026-07-26-pnpm-action-setup-for-symmetric-ci-caching.zh.md b/.agents/notes/proposed/process/2026-07-26-pnpm-action-setup-for-symmetric-ci-caching.zh.md
deleted file mode 100644
index 2348e07d58..0000000000
--- a/.agents/notes/proposed/process/2026-07-26-pnpm-action-setup-for-symmetric-ci-caching.zh.md
+++ /dev/null
@@ -1,31 +0,0 @@
-# Agent Note: 用 pnpm/action-setup 实现对称的 CI pnpm 缓存
-
-Status: proposed
-
-[English](2026-07-26-pnpm-action-setup-for-symmetric-ci-caching.md) | 中文
-
-## 问题
-
-五个工作流重复着同一套手写（hand-rolled）的三步 pnpm 设置——`corepack enable`、`pnpm store path --silent >> $GITHUB_OUTPUT`、再加以 `pnpm-lock.yaml` 为缓存键的 `actions/cache@v4`：`e2e.yml`、`docs-pages.yml`、`pi-ai-provider-e2e.yml`、`build-exe-for-python-sdk.yml`，以及 `ci.yml` 的 node-compat、serial-linux 与 benchmark 作业（合计约 40–60 行 YAML）。与之等价、由官方维护的做法——`pnpm/action-setup@v4`（从 package.json 读取 `packageManager`）加带 `cache: pnpm` 的 `actions/setup-node`——已在仓库内的 `landlock-run.yml` 中得到验证，同时还能隔绝 corepack 被从较新 Node 发行版中移除的影响。
-
-## 提案
-
-将各对称缓存工作流改为 `pnpm/action-setup@v4` + `setup-node` `cache: pnpm`。以下明确不做转换：
-
-- `ci.yml` 中运行在企业 runner 上的三个 PR（Pull Request）作业——它们刻意只用 `actions/cache/restore`，把缓存压缩/上传挡在付费且延迟敏感的关键路径之外，这种不对称是 `setup-node` 的缓存无法表达的；
-- Windows 作业，它刻意跳过 store 缓存。
-
-## 曾考虑的替代方案
-
-- **保留手写步骤。** 它们能用，但那是五份会各自漂移的设置样板副本，而且对 corepack 的依赖是已知的未来失效点。
-- **连企业作业在内全部转换。** 否决：只恢复不上传（restore-only）的不对称是 `ci.yml` 注释中有记录的延迟决策；为统一工具而抹掉它，属于颠倒优先级。
-
-## 验收标准
-
-- 五个对称工作流经由上述 action 完成 pnpm 设置；每条泳道各跑一次冷运行以重建新的缓存键格式，此后缓存命中率与旧步骤持平。
-- 企业 runner 上的 PR 作业与 Windows 作业保持原样不动。
-
-## 风险
-
-- 缓存键格式变更一次（每条泳道各一次冷运行）。
-- 更多工作流引入一个第三方 action；它已在仓库内获得信任（`landlock-run.yml`），且是 pnpm 团队的官方 action。
diff --git a/.github/workflows/build-exe-for-python-sdk.yml b/.github/workflows/build-exe-for-python-sdk.yml
index 48c96e4d20..b119a548b8 100644
--- a/.github/workflows/build-exe-for-python-sdk.yml
+++ b/.github/workflows/build-exe-for-python-sdk.yml
@@ -124,9 +124,14 @@ jobs:
     steps:
       - uses: actions/checkout@v6
 
+      - uses: pnpm/action-setup@v4
+
+      # setup-node's built-in pnpm store cache keys on platform AND arch, so
+      # the Linux architectures sharing runner.os stay on separate caches.
       - uses: actions/setup-node@v6
         with:
           node-version: 24
+          cache: pnpm
 
       - uses: actions/setup-python@v6
         with:
@@ -135,21 +140,6 @@ jobs:
       - name: Install Python build tooling
         run: python -m pip install uv==0.11.23
 
-      - name: Enable corepack (pnpm)
-        run: corepack enable
-
-      - name: Resolve pnpm store path
-        id: pnpm-store
-        run: echo "path=$(pnpm store path --silent)" >> "$GITHUB_OUTPUT"
-
-      # Linux architectures share runner.os, so the cache key includes arch.
-      - uses: actions/cache@v4
-        with:
-          path: ${{ steps.pnpm-store.outputs.path }}
-          key: ${{ runner.os }}-${{ runner.arch }}-node-24-pnpm-${{ hashFiles('pnpm-lock.yaml') }}
-          restore-keys: |
-            ${{ runner.os }}-${{ runner.arch }}-node-24-pnpm-
-
       # Cache pkg's target Node binary; lockfile changes roll the
       # exact key while the restore prefix can seed its replacement.
       - uses: actions/cache@v4
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e3b519130e..615aaf8fc1 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -58,25 +58,33 @@ jobs:
           fetch-depth: 0
           persist-credentials: false
 
+      - uses: pnpm/action-setup@v4
+
+      - uses: actions/setup-node@v6
+        with:
+          node-version: ${{ env.PRIMARY_NODE_VERSION }}
+
+      - name: Configure pnpm store path
+        id: pnpm-store
+        run: |
+          store_root="$HOME/.local/share/pnpm/store"
+          echo "PNPM_CONFIG_STORE_DIR=$store_root" >> "$GITHUB_ENV"
+          store_path=$(PNPM_CONFIG_STORE_DIR="$store_root" pnpm store path --silent)
+          echo "path=$store_path" >> "$GITHUB_OUTPUT"
+
       # Pull requests consume the default-branch cache but do not put cache
       # compression and upload on the paid latency-critical path. Skipped
       # under failover — see the coverage lane's identical rationale.
       - uses: actions/cache/restore@v4
         if: vars.DSH_CI_FAILOVER != 'selfhosted' || github.event.pull_request.user.login == 'dependabot[bot]'
         with:
-          path: /home/runner/.local/share/pnpm/store/v11
+          path: ${{ steps.pnpm-store.outputs.path }}
           key: ${{ runner.os }}-node-${{ env.PRIMARY_NODE_VERSION }}-pnpm-${{ hashFiles('pnpm-lock.yaml') }}
           restore-keys: |
             ${{ runner.os }}-node-${{ env.PRIMARY_NODE_VERSION }}-pnpm-
 
-      - uses: actions/setup-node@v6
-        with:
-          node-version: ${{ env.PRIMARY_NODE_VERSION }}
-
-      - name: Enable corepack and install dependencies
-        run: |
-          corepack enable
-          pnpm install --frozen-lockfile
+      - name: Install (immutable)
+        run: pnpm install --frozen-lockfile
 
       - name: Run static gates
         env:
@@ -117,24 +125,33 @@ jobs:
         with:
           persist-credentials: false
 
-      # Skipped under failover: the self-hosted VM's persistent pnpm store
-      # serves warm installs directly, and this hosted-path restore would
-      # spend ~52 s pulling ~180 MB into a path pnpm never reads there.
-      - uses: actions/cache/restore@v4
-        if: vars.DSH_CI_FAILOVER != 'selfhosted' || github.event.pull_request.user.login == 'dependabot[bot]'
-        with:
-          path: /home/runner/.local/share/pnpm/store/v11
-          key: ${{ runner.os }}-node-${{ env.PRIMARY_NODE_VERSION }}-pnpm-${{ hashFiles('pnpm-lock.yaml') }}
-          restore-keys: |
-            ${{ runner.os }}-node-${{ env.PRIMARY_NODE_VERSION }}-pnpm-
+      - uses: pnpm/action-setup@v4
 
       - uses: actions/setup-node@v6
         with:
           node-version: ${{ env.PRIMARY_NODE_VERSION }}
 
-      - name: Enable corepack, install dependencies, and prepare bubblewrap
+      - name: Configure pnpm store path
+        id: pnpm-store
+        run: |
+          store_root="$HOME/.local/share/pnpm/store"
+          echo "PNPM_CONFIG_STORE_DIR=$store_root" >> "$GITHUB_ENV"
+          store_path=$(PNPM_CONFIG_STORE_DIR="$store_root" pnpm store path --silent)
+          echo "path=$store_path" >> "$GITHUB_OUTPUT"
+
+      # Skipped under failover: the self-hosted VM's persistent pnpm store
+      # already serves warm installs, while restoring the hosted archive
+      # would spend ~52 s pulling ~180 MB into that populated store.
+      - uses: actions/cache/restore@v4
+        if: vars.DSH_CI_FAILOVER != 'selfhosted' || github.event.pull_request.user.login == 'dependabot[bot]'
+        with:
+          path: ${{ steps.pnpm-store.outputs.path }}
+          key: ${{ runner.os }}-node-${{ env.PRIMARY_NODE_VERSION }}-pnpm-${{ hashFiles('pnpm-lock.yaml') }}
+          restore-keys: |
+            ${{ runner.os }}-node-${{ env.PRIMARY_NODE_VERSION }}-pnpm-
+
+      - name: Install dependencies and prepare bubblewrap
         run: |
-          corepack enable
           pnpm install --frozen-lockfile &
           install_pid=$!
           bash scripts/prepare-ci-bubblewrap.sh &
@@ -179,15 +196,6 @@ jobs:
       - name: Restore built tree
         run: tar -xzf "$RUNNER_TEMP/node-24-built-tree.tar.gz"
 
-      # Skipped under failover — see the coverage lane's identical rationale.
-      - uses: actions/cache/restore@v4
-        if: vars.DSH_CI_FAILOVER != 'selfhosted' || github.event.pull_request.user.login == 'dependabot[bot]'
-        with:
-          path: /home/runner/.local/share/pnpm/store/v11
-          key: ${{ runner.os }}-node-${{ env.PRIMARY_NODE_VERSION }}-pnpm-${{ hashFiles('pnpm-lock.yaml') }}
-          restore-keys: |
-            ${{ runner.os }}-node-${{ env.PRIMARY_NODE_VERSION }}-pnpm-
-
       - uses: actions/cache/restore@v4
         with:
           path: .cache/eslint
@@ -195,13 +203,31 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-node-${{ env.PRIMARY_NODE_VERSION }}-eslint-full-
 
+      - uses: pnpm/action-setup@v4
+
       - uses: actions/setup-node@v6
         with:
           node-version: ${{ env.PRIMARY_NODE_VERSION }}
 
-      - name: Enable corepack, install dependencies, and prepare bubblewrap
+      - name: Configure pnpm store path
+        id: pnpm-store
+        run: |
+          store_root="$HOME/.local/share/pnpm/store"
+          echo "PNPM_CONFIG_STORE_DIR=$store_root" >> "$GITHUB_ENV"
+          store_path=$(PNPM_CONFIG_STORE_DIR="$store_root" pnpm store path --silent)
+          echo "path=$store_path" >> "$GITHUB_OUTPUT"
+
+      # Skipped under failover — see the coverage lane's identical rationale.
+      - uses: actions/cache/restore@v4
+        if: vars.DSH_CI_FAILOVER != 'selfhosted' || github.event.pull_request.user.login == 'dependabot[bot]'
+        with:
+          path: ${{ steps.pnpm-store.outputs.path }}
+          key: ${{ runner.os }}-node-${{ env.PRIMARY_NODE_VERSION }}-pnpm-${{ hashFiles('pnpm-lock.yaml') }}
+          restore-keys: |
+            ${{ runner.os }}-node-${{ env.PRIMARY_NODE_VERSION }}-pnpm-
+
+      - name: Install dependencies and prepare bubblewrap
         run: |
-          corepack enable
           pnpm install --frozen-lockfile &
           install_pid=$!
           bash scripts/prepare-ci-bubblewrap.sh &
@@ -277,22 +303,12 @@ jobs:
     steps:
       - uses: actions/checkout@v6
 
+      - uses: pnpm/action-setup@v4
+
       - uses: actions/setup-node@v6
         with:
           node-version: ${{ matrix.node }}
-
-      - name: Enable corepack and resolve pnpm store path
-        id: pnpm-store
-        run: |
-          corepack enable
-          echo "path=$(pnpm store path --silent)" >> "$GITHUB_OUTPUT"
-
-      - uses: actions/cache@v4
-        with:
-          path: ${{ steps.pnpm-store.outputs.path }}
-          key: ${{ runner.os }}-node-${{ matrix.node }}-pnpm-${{ hashFiles('pnpm-lock.yaml') }}
-          restore-keys: |
-            ${{ runner.os }}-node-${{ matrix.node }}-pnpm-
+          cache: pnpm
 
       - name: Install (immutable)
         run: pnpm install --frozen-lockfile
@@ -342,13 +358,23 @@ jobs:
         with:
           persist-credentials: false
 
+      - uses: pnpm/action-setup@v4
+
       - uses: actions/setup-node@v6
         with:
           node-version: ${{ env.PRIMARY_NODE_VERSION }}
 
+      - name: Configure pnpm store path
+        id: pnpm-store
+        run: |
+          store_root="$HOME/.local/share/pnpm/store"
+          echo "PNPM_CONFIG_STORE_DIR=$store_root" >> "$GITHUB_ENV"
+          store_path=$(PNPM_CONFIG_STORE_DIR="$store_root" pnpm store path --silent)
+          echo "path=$store_path" >> "$GITHUB_OUTPUT"
+
       - uses: actions/cache/restore@v4
         with:
-          path: /home/runner/.local/share/pnpm/store/v11
+          path: ${{ steps.pnpm-store.outputs.path }}
           key: ${{ runner.os }}-node-${{ env.PRIMARY_NODE_VERSION }}-pnpm-${{ hashFiles('pnpm-lock.yaml') }}
           restore-keys: |
             ${{ runner.os }}-node-${{ env.PRIMARY_NODE_VERSION }}-pnpm-
@@ -367,8 +393,6 @@ jobs:
 
       - name: Install dependencies and provision Wine concurrently
         run: |
-          corepack enable
-
           # Windows-lane install-time overrides. supportedArchitectures
           # additionally materializes the win32-x64 platform packages
           # (@esbuild/win32-x64, rolldown and rollup MSVC bindings) the
@@ -550,17 +574,26 @@ jobs:
         with:
           fetch-depth: 2
 
+      - uses: pnpm/action-setup@v4
+
       - uses: actions/setup-node@v6
         with:
           node-version: ${{ env.PRIMARY_NODE_VERSION }}
 
-      - name: Enable corepack and resolve pnpm store path
+      - name: Configure pnpm store path
         id: pnpm-store
         run: |
-          corepack enable
-          echo "path=$(pnpm store path --silent)" >> "$GITHUB_OUTPUT"
+          store_root="$HOME/.local/share/pnpm/store"
+          echo "PNPM_CONFIG_STORE_DIR=$store_root" >> "$GITHUB_ENV"
+          store_path=$(PNPM_CONFIG_STORE_DIR="$store_root" pnpm store path --silent)
+          echo "path=$store_path" >> "$GITHUB_OUTPUT"
 
       # Master refreshes the caches that pull requests restore without saving.
+      # The store cache stays a hand-rolled actions/cache step rather than
+      # setup-node's `cache: pnpm`: the enterprise pull-request jobs above
+      # restore exactly this key and path, and setup-node's built-in cache
+      # uses its own key format — converting this producer would silently
+      # starve their documented restore-only optimization.
       - uses: actions/cache@v4
         with:
           path: ${{ steps.pnpm-store.outputs.path }}
@@ -618,12 +651,14 @@ jobs:
         with:
           fetch-depth: 0
 
+      - uses: pnpm/action-setup@v4
+
       - uses: actions/setup-node@v6
         with:
           node-version: ${{ env.PRIMARY_NODE_VERSION }}
 
-      - name: Enable corepack (pnpm)
-        run: corepack enable
+      - name: Configure persistent pnpm store
+        run: echo "PNPM_CONFIG_STORE_DIR=$HOME/.local/share/pnpm/store" >> "$GITHUB_ENV"
 
       - name: Install (immutable)
         run: pnpm install --frozen-lockfile
@@ -649,13 +684,12 @@ jobs:
     steps:
       - uses: actions/checkout@v6
 
+      - uses: pnpm/action-setup@v4
+
       - uses: actions/setup-node@v6
         with:
           node-version: ${{ env.PRIMARY_NODE_VERSION }}
 
-      - name: Enable corepack (pnpm)
-        run: corepack enable
-
       - name: Install (immutable)
         run: pnpm install --frozen-lockfile
 
@@ -681,14 +715,12 @@ jobs:
           reg add "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\AppModelUnlock"
           /t REG_DWORD /f /v "AllowDevelopmentWithoutDevLicense" /d "1"
 
+      - uses: pnpm/action-setup@v4
+
       - uses: actions/setup-node@v6
         with:
           node-version: ${{ env.PRIMARY_NODE_VERSION }}
 
-      - name: Enable corepack (pnpm)
-        shell: pwsh
-        run: corepack enable
-
       # Master refreshes the small cache that pull requests restore without
       # putting package-store extraction back on the Windows critical path.
       - uses: actions/cache@v4
@@ -775,9 +807,14 @@ jobs:
     steps:
       - uses: actions/checkout@v6
 
+      - uses: pnpm/action-setup@v4
+
+      # The Windows lanes deliberately skip the store cache like the required
+      # windows job; an empty cache input disables setup-node's caching.
       - uses: actions/setup-node@v6
         with:
           node-version: ${{ env.PRIMARY_NODE_VERSION }}
+          cache: ${{ matrix.platform == 'linux' && 'pnpm' || '' }}
 
       - name: Report runner capacity
         run: >-
@@ -785,22 +822,6 @@ jobs:
           console.log(JSON.stringify({ arch: process.arch, cpus: os.cpus().length,
           memoryGiB: Math.round(os.totalmem() / 2 ** 30) }))"
 
-      - name: Enable corepack (pnpm)
-        run: corepack enable
-
-      - name: Resolve pnpm store path
-        if: matrix.platform == 'linux'
-        id: pnpm-store
-        run: echo "path=$(pnpm store path --silent)" >> "$GITHUB_OUTPUT"
-
-      - uses: actions/cache@v4
-        if: matrix.platform == 'linux'
-        with:
-          path: ${{ steps.pnpm-store.outputs.path }}
-          key: ${{ runner.os }}-node-${{ env.PRIMARY_NODE_VERSION }}-pnpm-${{ hashFiles('pnpm-lock.yaml') }}
-          restore-keys: |
-            ${{ runner.os }}-node-${{ env.PRIMARY_NODE_VERSION }}-pnpm-
-
       - name: Install (immutable)
         run: pnpm install --frozen-lockfile
 
@@ -875,9 +896,14 @@ jobs:
     steps:
       - uses: actions/checkout@v6
 
+      - uses: pnpm/action-setup@v4
+
+      # Unlike the larger-runner suite, both platforms cache the store here:
+      # the consolidated topology measures cache mechanics as workload.
       - uses: actions/setup-node@v6
         with:
           node-version: ${{ env.PRIMARY_NODE_VERSION }}
+          cache: pnpm
 
       - name: Report runner capacity
         run: >-
@@ -885,27 +911,6 @@ jobs:
           console.log(JSON.stringify({ arch: process.arch, cpus: os.cpus().length,
           memoryGiB: Math.round(os.totalmem() / 2 ** 30) }))"
 
-      - name: Enable corepack (pnpm)
-        run: corepack enable
-
-      - name: Resolve pnpm store path (Linux)
-        if: matrix.platform == 'linux'
-        id: pnpm-store-linux
-        run: echo "path=$(pnpm store path --silent)" >> "$GITHUB_OUTPUT"
-
-      - name: Resolve pnpm store path (Windows)
-        if: matrix.platform == 'windows'
-        id: pnpm-store-windows
-        shell: pwsh
-        run: '"path=$(pnpm store path --silent)" >> $env:GITHUB_OUTPUT'
-
-      - uses: actions/cache@v4
-        with:
-          path: ${{ steps.pnpm-store-linux.outputs.path || steps.pnpm-store-windows.outputs.path }}
-          key: ${{ runner.os }}-node-${{ env.PRIMARY_NODE_VERSION }}-pnpm-${{ hashFiles('pnpm-lock.yaml') }}
-          restore-keys: |
-            ${{ runner.os }}-node-${{ env.PRIMARY_NODE_VERSION }}-pnpm-
-
       - uses: actions/cache@v4
         if: matrix.platform == 'linux'
         with:
diff --git a/.github/workflows/docs-pages.yml b/.github/workflows/docs-pages.yml
index e1ad20997d..281e931c50 100644
--- a/.github/workflows/docs-pages.yml
+++ b/.github/workflows/docs-pages.yml
@@ -33,23 +33,12 @@ jobs:
     steps:
       - uses: actions/checkout@v6
 
+      - uses: pnpm/action-setup@v4
+
       - uses: actions/setup-node@v6
         with:
           node-version: ${{ env.PRIMARY_NODE_VERSION }}
-
-      - name: Enable corepack (pnpm)
-        run: corepack enable
-
-      - name: Resolve pnpm store path
-        id: pnpm-store
-        run: echo "path=$(pnpm store path --silent)" >> "$GITHUB_OUTPUT"
-
-      - uses: actions/cache@v4
-        with:
-          path: ${{ steps.pnpm-store.outputs.path }}
-          key: ${{ runner.os }}-node-${{ env.PRIMARY_NODE_VERSION }}-pnpm-${{ hashFiles('pnpm-lock.yaml') }}
-          restore-keys: |
-            ${{ runner.os }}-node-${{ env.PRIMARY_NODE_VERSION }}-pnpm-
+          cache: pnpm
 
       - name: Install (immutable)
         run: pnpm install --frozen-lockfile
diff --git a/.github/workflows/e2e.yml b/.github/workflows/e2e.yml
index 3d1bba6c17..c445034a8c 100644
--- a/.github/workflows/e2e.yml
+++ b/.github/workflows/e2e.yml
@@ -61,23 +61,12 @@ jobs:
     steps:
       - uses: actions/checkout@v6
 
+      - uses: pnpm/action-setup@v4
+
       - uses: actions/setup-node@v6
         with:
           node-version: 24
-
-      - name: Enable corepack (pnpm)
-        run: corepack enable
-
-      - name: Resolve pnpm store path
-        id: pnpm-store
-        run: echo "path=$(pnpm store path --silent)" >> "$GITHUB_OUTPUT"
-
-      - uses: actions/cache@v4
-        with:
-          path: ${{ steps.pnpm-store.outputs.path }}
-          key: ${{ runner.os }}-node-24-pnpm-${{ hashFiles('pnpm-lock.yaml') }}
-          restore-keys: |
-            ${{ runner.os }}-node-24-pnpm-
+          cache: pnpm
 
       - name: Install (immutable)
         run: pnpm install --frozen-lockfile
diff --git a/.github/workflows/pi-ai-provider-e2e.yml b/.github/workflows/pi-ai-provider-e2e.yml
index d198abf5b5..1306754d4c 100644
--- a/.github/workflows/pi-ai-provider-e2e.yml
+++ b/.github/workflows/pi-ai-provider-e2e.yml
@@ -27,23 +27,12 @@ jobs:
     steps:
       - uses: actions/checkout@v6
 
+      - uses: pnpm/action-setup@v4
+
       - uses: actions/setup-node@v6
         with:
           node-version: 24
-
-      - name: Enable corepack (pnpm)
-        run: corepack enable
-
-      - name: Resolve pnpm store path
-        id: pnpm-store
-        run: echo "path=$(pnpm store path --silent)" >> "$GITHUB_OUTPUT"
-
-      - uses: actions/cache@v4
-        with:
-          path: ${{ steps.pnpm-store.outputs.path }}
-          key: ${{ runner.os }}-node-24-pnpm-${{ hashFiles('pnpm-lock.yaml') }}
-          restore-keys: |
-            ${{ runner.os }}-node-24-pnpm-
+          cache: pnpm
 
       - name: Install (immutable)
         run: pnpm install --frozen-lockfile
diff --git a/.github/workflows/sandbox.yml b/.github/workflows/sandbox.yml
index 51dfe06f1c..0d14914bfd 100644
--- a/.github/workflows/sandbox.yml
+++ b/.github/workflows/sandbox.yml
@@ -53,13 +53,12 @@ jobs:
     steps:
       - uses: actions/checkout@v6
 
+      - uses: pnpm/action-setup@v4
+
       - uses: actions/setup-node@v6
         with:
           node-version: 24
 
-      - name: Enable corepack (pnpm)
-        run: corepack enable
-
       - name: Install (immutable)
         run: pnpm install --frozen-lockfile
 
diff --git a/knip.json b/knip.json
index 110abb3a2b..7ab7d47e5f 100644
--- a/knip.json
+++ b/knip.json
@@ -13,6 +13,7 @@
     "python/sdk-runtime"
   ],
   "ignoreDependencies": [
+    "@yarnpkg/cli-dist",
     "lightningcss"
   ],
   "workspaces": {
diff --git a/package.json b/package.json
index 3aa3d6998a..27f192466c 100644
--- a/package.json
+++ b/package.json
@@ -113,9 +113,10 @@
     "@types/mdast": "^4.0.4",
     "@types/node": "^22.20.0",
     "@vitest/coverage-v8": "^4.1.8",
+    "@yarnpkg/cli-dist": "4.17.1",
     "eslint": "^10.4.1",
-    "execa": "^10.0.0",
     "eslint-plugin-sonarjs": "^4.1.0",
+    "execa": "^10.0.0",
     "fast-check": "^4.8.0",
     "js-yaml": "^4.2.0",
     "jscpd": "^5.0.12",
diff --git a/packages/sdk/create-sdk/tests/link-workspace.e2e.ts b/packages/sdk/create-sdk/tests/link-workspace.e2e.ts
index 0fefefdffa..7d1944614d 100644
--- a/packages/sdk/create-sdk/tests/link-workspace.e2e.ts
+++ b/packages/sdk/create-sdk/tests/link-workspace.e2e.ts
@@ -90,6 +90,8 @@ describe.skipIf(!existsSync(builtScripts))('live-linked generated projects', ()
         XDG_DATA_HOME: join(cacheRoot, 'data'),
         npm_config_cache: join(cacheRoot, 'npm'),
         ...pnpmStore === undefined ? {} : { pnpm_config_store_dir: pnpmStore },
+        // A generated project has no lockfile yet; ambient CI must not make its first Yarn install immutable.
+        ...name === 'yarn' ? { YARN_ENABLE_IMMUTABLE_INSTALLS: 'false' } : {},
       }
       await execFileAsync(name, manager.installCommand(), {
         cwd: root,
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index f82de24032..a24a701f61 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -35,6 +35,9 @@ importers:
       '@vitest/coverage-v8':
         specifier: ^4.1.8
         version: 4.1.8(vitest@4.1.8)
+      '@yarnpkg/cli-dist':
+        specifier: 4.17.1
+        version: 4.17.1
       eslint:
         specifier: ^10.4.1
         version: 10.5.0(jiti@2.7.0)
@@ -7468,6 +7471,11 @@ packages:
   '@xterm/headless@5.5.0':
     resolution: {integrity: sha512-5xXB7kdQlFBP82ViMJTwwEc3gKCLGKR/eoxQm4zge7GPBl86tCdI0IdPJjoKd8mUSFXz5V7i/25sfsEkP4j46g==}
 
+  '@yarnpkg/cli-dist@4.17.1':
+    resolution: {integrity: sha512-2tiSQuJNl/L3QwTdrq6lKWDpkcnp9MGvCT/rIldHcbu3SWfnLdmehvt3eulX1hT7FFt1Gjfq3CesF+kvhFip6g==}
+    engines: {node: '>=18.12.0'}
+    hasBin: true
+
   accepts@2.0.0:
     resolution: {integrity: sha512-5cvg6CtKwfgdmVqY1WIiXKc3Q1bkRqGLi+2W/6ao+6Y7gu/RCwRuAhGEzh5B4KlszSuTLgZYuqFqo5bImjNKng==}
     engines: {node: '>= 0.6'}
@@ -12364,6 +12372,8 @@ snapshots:
 
   '@xterm/headless@5.5.0': {}
 
+  '@yarnpkg/cli-dist@4.17.1': {}
+
   accepts@2.0.0:
     dependencies:
       mime-types: 3.0.2