refactor(picker): drop the Windows PowerShell fallback chain

The win32 tier is exactly the koffi IFileOpenDialog child process; any failure surfaces as-is. The pwsh -> Windows PowerShell 5.1 cascade, the shared WinForms script, and the triple-miss AggregateError are deleted: koffi is a packaged dependency whose availability the install guarantees, so no mechanism fallback exists (the browse backend remains the fallback at the composition level). The pwsh-first DPI picker-fix note is consolidated into a new simplification note recording the reversal.

.agents/notes/implemented/feature/2026-07-27-native-workspace-directory-picker.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/feature/2026-07-27-native-workspace-directory-picker.md
-2026-07-27-native-workspace-directory-picker.md: 452ec60371558de79dbff964a12d96d2150dc6f6
-2026-07-27-native-workspace-directory-picker.zh.md: c3e6b8825e78201ce791cff51869aade67d30a5e
+2026-07-27-native-workspace-directory-picker.md: a36f7b239a9115fe5eb33472ec5084818a66e9f2
+2026-07-27-native-workspace-directory-picker.zh.md: bb3e2fc6f7c77c8ace97e53435297326f937e4e8

.agents/notes/implemented/feature/2026-07-27-native-workspace-directory-picker.md

@@ -30,7 +30,7 @@ The native dialog RPC is accepted only from a loopback socket with same-origin b
 Platform adapters open the dialog without a shell — spawned native tools on POSIX, an in-process COM conversation on Windows:
 
 - macOS: `osascript` and the system folder chooser.
-- Windows: the in-process koffi `IFileOpenDialog` worker with the best thread DPI awareness the host accepts (per-monitor-v2 when available; PMv2-less hosts cascade to per-monitor or system-aware) ([in-process dialog note](2026-08-02-win32-in-process-folder-dialog.md)); the PowerShell chain (`pwsh` in STA mode, then Windows PowerShell 5.1, both DPI-corrected) remains the fallback ([picker fix](../bug-fix/2026-08-01-windows-picker-pwsh-dpi.md)).
+- Windows: the koffi `IFileOpenDialog` child process with the best thread DPI awareness the host accepts (per-monitor-v2 when available; PMv2-less hosts cascade to per-monitor or system-aware) ([in-process dialog note](2026-08-02-win32-in-process-folder-dialog.md)); the tier has no fallback — failures surface as-is ([PowerShell chain removal](../simplification/2026-08-04-drop-windows-powershell-picker-fallback.md)).
 - Linux: `zenity`, with `kdialog` as a fallback when Zenity is unavailable.
 
 ## Alternatives considered

.agents/notes/implemented/feature/2026-07-27-native-workspace-directory-picker.zh.md

@@ -27,10 +27,10 @@ Status: implemented
 
 只有来自回环套接字、且携带同源浏览器元数据的请求才能调用原生对话框 RPC。该 RPC 不使用默认的 30 秒请求超时，因为系统对话框可能无限期保持打开；调用方中止或连接中止仍会传递至平台进程。
 
-平台适配器不经 shell 打开对话框——POSIX 上 spawn 原生工具，Windows 上是进程内 COM 会话：
+平台适配器不经 shell 打开对话框——POSIX 上 spawn 原生工具，Windows 上是子进程 COM 会话：
 
 - macOS：`osascript` 和系统文件夹选择器。
-- Windows：进程内 koffi `IFileOpenDialog` worker，使用宿主接受的最佳线程 DPI 感知（可用时为 per-monitor-v2；不支持 PMv2 的主机级联到 per-monitor 或 system-aware）（见[进程内对话框 Note](2026-08-02-win32-in-process-folder-dialog.md)）；PowerShell 链（STA 模式的 `pwsh`，再到 Windows PowerShell 5.1，均已修正 DPI）保留为回退（见[选择器修复](../bug-fix/2026-08-01-windows-picker-pwsh-dpi.md)）。
+- Windows：koffi `IFileOpenDialog` 子进程，使用宿主接受的最佳线程 DPI 感知（可用时为 per-monitor-v2；不支持 PMv2 的主机级联到 per-monitor 或 system-aware）（见[进程内对话框 Note](2026-08-02-win32-in-process-folder-dialog.md)）；该层无回退——失败原样上报（见[PowerShell 链删除](../simplification/2026-08-04-drop-windows-powershell-picker-fallback.md)）。
 - Linux：使用 `zenity`；Zenity 不可用时回退到 `kdialog`。
 
 ## 考虑过的替代方案

.agents/notes/implemented/feature/2026-08-02-win32-in-process-folder-dialog.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/feature/2026-08-02-win32-in-process-folder-dialog.md
-2026-08-02-win32-in-process-folder-dialog.md: c7a6602836c618e855c799b72017aa9232eda968
-2026-08-02-win32-in-process-folder-dialog.zh.md: a67a22625dcd674b2a63b6125b3d31704e90eabc
+2026-08-02-win32-in-process-folder-dialog.md: 91a1ed0d7b1c1938a5e038ce36f1ca90bf3c9e82
+2026-08-02-win32-in-process-folder-dialog.zh.md: 6b90dc1c5fa0042b3e2bcbea8ed554f1f0ea2acf

.agents/notes/implemented/feature/2026-08-02-win32-in-process-folder-dialog.md

@@ -1,4 +1,4 @@
-# Agent Note: Win32 folder picker moves in-process over koffi
+# Agent Note: Win32 folder picker moves to koffi in a child process
 
 Status: implemented
 
@@ -10,18 +10,18 @@ The Windows directory picker's primary tier was a spawned PowerShell script arou
 
 ## Decision
 
-`packages/host/directory-picker-native` now opens `IFileOpenDialog` (`FOS_PICKFOLDERS | FOS_FORCEFILESYSTEM | FOS_NOCHANGEDIR`) in-process through koffi — already a workspace dependency for the repo's other `win32.ts` surfaces — as the primary win32 tier. The COM conversation runs on a `worker_threads` worker so the modal `Show` never blocks the host event loop; the worker posts its native thread id before blocking, and the driver services aborts by re-posting `WM_CLOSE` to that thread's windows (`EnumThreadWindows`), terminating and unrefing the worker only when the close budget is exhausted (Node cannot interrupt native calls, so an unclosable worker must never hold the process open). A window on a worker input queue would otherwise be shown without activation, so the driver also raises the dialog to the foreground once the worker reports `showing` — attaching input queues and calling `SetForegroundWindow`, retried on the close cadence until the window (created inside `Show`) exists. The worker thread opts into the best thread DPI awareness the host accepts (`SetThreadDpiAwarenessContext`, cascading per-monitor-v2 → per-monitor → system-aware with the return value checked), a strict upgrade over the script's system-DPI ceiling; DPI stays a cosmetic best-effort — a host accepting none of them still gets the modern dialog rather than a downgrade to the fallback chain. The module split keeps coverage honest on every host: `win32-dialog-logic.ts` (pure sequencing) and `win32-dialog.ts` (driver) test against fakes anywhere; `win32-dialog-bindings.ts` tests against a mocked `koffi` COM world (the `dsh-session-persistence-jsonl` technique); POSIX hosts run the real spawn plumbing to its koffi-load rejection; win32 hosts run a real open-and-abort-close smoke. That smoke lives in `processBoundTests`: under the threads pool a worker blocked in a native modal wedges pool teardown, while a fork contains it. The PowerShell chain (see the [DPI note](../bug-fix/2026-08-01-windows-picker-pwsh-dpi.md)) stays as the fallback tier, its trigger widened from `ENOENT` to any pwsh failure, which also closes the PowerShell 6 regression.
+`packages/host/directory-picker-native` now opens `IFileOpenDialog` (`FOS_PICKFOLDERS | FOS_FORCEFILESYSTEM | FOS_NOCHANGEDIR`) in-process through koffi — already a workspace dependency for the repo's other `win32.ts` surfaces — as the primary win32 tier. The COM conversation runs in a spawned child process so the modal `Show` never blocks the host event loop; the child posts its native thread id before blocking, and the driver services aborts by re-posting `WM_CLOSE` to that thread's windows (`EnumThreadWindows`), killing the child when the close budget is exhausted. The dialog is the child's first window, so Windows activates it without a foreground call. The child thread opts into the best thread DPI awareness the host accepts (`SetThreadDpiAwarenessContext`, cascading per-monitor-v2 → per-monitor → system-aware with the return value checked), a strict upgrade over the script's system-DPI ceiling; DPI stays a cosmetic best-effort — a host accepting none of them still gets the modern dialog rather than a downgrade. The module split keeps coverage honest on every host: `win32-dialog-logic.ts` (pure sequencing) and `win32-dialog.ts` (driver) test against fakes anywhere; `win32-dialog-bindings.ts` tests against a mocked `koffi` COM world (the `dsh-session-persistence-jsonl` technique); POSIX hosts run the real spawn plumbing to its koffi-load rejection; win32 hosts run a real open-and-abort-close smoke. The PowerShell chain that preceded this tier is gone (see the [chain removal](../simplification/2026-08-04-drop-windows-powershell-picker-fallback.md)): the tier has no fallback.
 
 ## Alternatives considered
 
 - **A prebuilt native helper (`native/` family like `node-addon-landlock-run`).** Rejected: a mirror repository, an npm package family, MSVC provisioning, and a release handoff — all to ship ~150 lines of C the repository cannot exercise on CI (no real-Windows lane); koffi delivers the same COM surface with zero new supply chain.
-- **An N-API in-process addon.** Rejected for the same CI/toolchain reasons plus owned C++ for STA threading and message pumping that `worker_threads` + koffi express in TypeScript.
+- **An N-API in-process addon.** Rejected for the same CI/toolchain reasons plus owned C++ for STA threading and message pumping that a child process + koffi express in TypeScript.
 - **Keep PowerShell primary and probe versions.** Rejected: the picker stays hostage to shell packaging (6 vs 7, Store aliases, profiles), and 5.1's legacy dialog remains the floor wherever pwsh is absent; the fallback-trigger widening alone was accepted into the fallback tier instead.
 - **Blocking the main thread for the modal call.** Rejected outright: the web host must keep serving RPC while the dialog is open.
 
 ## Consequences
 
-- Every Windows machine gets the modern dialog with the best DPI awareness it supports (per-monitor-v2 on 1703+), PowerShell installed or not; the PowerShell tiers only serve hosts where koffi cannot drive COM.
-- Real dialog rendering and the selection path stay a manual Windows check (the auto-close smoke proves open/abort/unwind); a wedged abort can leak one dialog thread until process exit, documented in the package README.
-- The COM vtable slots and GUIDs used are frozen Windows ABI (Vista); a koffi signature mistake is a native-crash risk that can take down the whole Node process — `worker_threads` share the process, so an access violation is not contained to the worker and no PowerShell fallback runs. The mocked-koffi ABI pins and the real win32 smoke exist to catch such mistakes before shipping.
-- The packaged-binary VFS arm — resolution of `./worker.cjs` inside a pkg snapshot — is not exercised by any automated test: the source worker and the built `lib/worker.cjs` under plain Node are covered, and the VFS-specific spawn remains deferred to the Windows CI roadmap.
+- Every Windows machine gets the modern dialog with the best DPI awareness it supports (per-monitor-v2 on 1703+), PowerShell installed or not.
+- Real dialog rendering and the selection path stay a manual Windows check (the auto-close smoke proves open/abort/unwind).
+- The COM vtable slots and GUIDs used are frozen Windows ABI (Vista); a koffi signature mistake risks a native access violation, contained to the dialog child process — the host Node process survives and the failure surfaces as-is (no fallback tier; see the [chain removal](../simplification/2026-08-04-drop-windows-powershell-picker-fallback.md)). The mocked-koffi ABI pins and the real win32 smoke exist to catch such mistakes before shipping.
+- The packaged-binary arm — the packaged executable spawning itself as the dialog entry — is not exercised by any automated test: the source plane and the built `lib/worker.cjs` under plain node are covered, and the packaged spawn remains deferred to the Windows CI roadmap.

.agents/notes/implemented/feature/2026-08-02-win32-in-process-folder-dialog.zh.md

@@ -1,4 +1,4 @@
-# Agent Note：Win32 文件夹选择器经 koffi 移入进程内
+# Agent Note：Win32 文件夹选择器迁至 koffi 子进程
 
 Status: implemented
 
@@ -10,18 +10,18 @@ Windows 目录选择器的主层此前是围绕 WinForms `FolderBrowserDialog`
 
 ## 决策
 
-`packages/host/directory-picker-native` 现在经 koffi——它已是仓库其他 `win32.ts` 面的工作区依赖——在进程内打开 `IFileOpenDialog`（`FOS_PICKFOLDERS | FOS_FORCEFILESYSTEM | FOS_NOCHANGEDIR`），作为 win32 主层。COM 会话运行在 `worker_threads` worker 上，模态 `Show` 永不阻塞宿主事件循环；worker 在阻塞前上报其原生线程 id，driver 通过向该线程的窗口反复投递 `WM_CLOSE`（`EnumThreadWindows`）来服务中止，仅当关闭预算耗尽时才 terminate 并 unref worker（Node 无法打断原生调用，关不掉的 worker 决不能拖住进程退出）。worker 输入队列上的窗口默认只会被显示而不会被激活，因此 driver 还会在 worker 上报 `showing` 后把对话框抬升到前台——附加输入队列并调用 `SetForegroundWindow`，按关闭节奏重试直到 `Show` 内创建的窗口出现。worker 线程启用宿主接受的最佳线程 DPI 感知（`SetThreadDpiAwarenessContext`，按 per-monitor-v2 → per-monitor → system-aware 级联并检查返回值），严格优于脚本的系统 DPI 上限；DPI 保持为纯外观的 best-effort——全部不被接受的宿主仍得到现代对话框，而不会降级到回退链。模块切分让覆盖率在任何主机上都诚实：`win32-dialog-logic.ts`（纯时序）与 `win32-dialog.ts`（driver）在任何平台对假件测试；`win32-dialog-bindings.ts` 对 mock 的 `koffi` COM 世界测试（`dsh-session-persistence-jsonl` 的技法）；POSIX 主机把真实 spawn 管道跑到 koffi 加载失败的拒绝；win32 主机跑真实的"打开并中止关闭"冒烟。该冒烟位于 `processBoundTests`：threads 池下阻塞在原生模态中的 worker 会卡死池的收尾，fork 则能容纳它。PowerShell 链（见 [DPI note](../bug-fix/2026-08-01-windows-picker-pwsh-dpi.md)）保留为回退层，触发条件从 `ENOENT` 拓宽为 pwsh 的任何失败，同时关闭了 PowerShell 6 回归。
+`packages/host/directory-picker-native` 现在经 koffi——它已是仓库其他 `win32.ts` 面的工作区依赖——在进程内打开 `IFileOpenDialog`（`FOS_PICKFOLDERS | FOS_FORCEFILESYSTEM | FOS_NOCHANGEDIR`），作为 win32 主层。COM 会话运行在 spawn 出的子进程中，模态 `Show` 永不阻塞宿主事件循环；子进程在阻塞前上报其原生线程 id，driver 通过向该线程的窗口反复投递 `WM_CLOSE`（`EnumThreadWindows`）来服务中止，关闭预算耗尽时 kill 子进程。对话框是子进程的第一个窗口，Windows 会自动激活它，无需手动前台调用。子进程线程启用宿主接受的最佳线程 DPI 感知（`SetThreadDpiAwarenessContext`，按 per-monitor-v2 → per-monitor → system-aware 级联并检查返回值），严格优于脚本的系统 DPI 上限；DPI 保持为纯外观的 best-effort——全部不被接受的宿主仍得到现代对话框，而不会降级。模块切分让覆盖率在任何主机上都诚实：`win32-dialog-logic.ts`（纯时序）与 `win32-dialog.ts`（driver）在任何平台对假件测试；`win32-dialog-bindings.ts` 对 mock 的 `koffi` COM 世界测试（`dsh-session-persistence-jsonl` 的技法）；POSIX 主机把真实 spawn 管道跑到 koffi 加载失败的拒绝；win32 主机跑真实的"打开并中止关闭"冒烟。先于本层存在的 PowerShell 链已被删除（见[链删除](../simplification/2026-08-04-drop-windows-powershell-picker-fallback.md)）：该层无回退。
 
 ## 考虑过的替代方案
 
 - **预编译原生助手（`native/` 家族，如 `node-addon-landlock-run`）。** 否决：镜像仓库、npm 包家族、MSVC 供给和发布交接——只为交付约 150 行 CI 无法执行的 C（没有真 Windows 通道）；koffi 以零新增供应链提供同一 COM 面。
-- **N-API 进程内插件。** 否决：同样的 CI／工具链原因，另加需要自有 C++ 处理 STA 线程与消息泵，而 `worker_threads` + koffi 用 TypeScript 就能表达。
+- **N-API 进程内插件。** 否决：同样的 CI／工具链原因，另加需要自有 C++ 处理 STA 线程与消息泵，而子进程 + koffi 用 TypeScript 就能表达。
 - **保留 PowerShell 为主层并探测版本。** 否决：选择器仍被 shell 打包形态挟持（6 与 7、Store 别名、profile），且没有 pwsh 的机器地板仍是 5.1 的旧版对话框；仅把回退触发条件的拓宽吸收进回退层。
 - **在主线程上阻塞模态调用。** 直接否决：对话框打开期间 web 宿主必须继续服务 RPC。
 
 ## 后果
 
-- 每台 Windows 机器都得到带其所支持的最佳 DPI 感知（1703+ 为 per-monitor-v2）的现代对话框，无论是否安装 PowerShell；PowerShell 层只服务 koffi 无法驱动 COM 的主机。
-- 真实对话框渲染与选中路径仍是手动 Windows 检查（自动关闭冒烟证明打开／中止／收尾）；卡死的中止可能泄漏一个对话框线程直到进程退出，已记录于包 README。
-- 所用 COM vtable 槽位与 GUID 是冻结的 Windows ABI（Vista 起）；koffi 签名错误是可能拖垮整个 Node 进程的原生崩溃风险——`worker_threads` 与主线程共享进程，访问冲突不会只局限在 worker 内，也不会进入 PowerShell 回退。mocked-koffi 的 ABI 钉与真实 win32 冒烟正是为了在交付前捕获这类错误。
-- 打包二进制的 VFS 臂——在 pkg 快照内解析 `./worker.cjs`——不受任何自动化测试覆盖：源码 worker 与普通 Node 下构建出的 `lib/worker.cjs` 已被覆盖，VFS 专属的 spawn 推迟到 Windows CI 路线图。
+- 每台 Windows 机器都得到带其所支持的最佳 DPI 感知（1703+ 为 per-monitor-v2）的现代对话框，无论是否安装 PowerShell。
+- 真实对话框渲染与选中路径仍是手动 Windows 检查（自动关闭冒烟证明打开／中止／收尾）。
+- 所用 COM vtable 槽位与 GUID 是冻结的 Windows ABI（Vista 起）；koffi 签名错误可能引发原生访问冲突，但被限制在对话框子进程内——宿主 Node 进程存活，失败原样上报（无回退层；见[链删除](../simplification/2026-08-04-drop-windows-powershell-picker-fallback.md)）。mocked-koffi 的 ABI 钉与真实 win32 冒烟正是为了在交付前捕获这类错误。
+- 打包二进制的臂——打包后的可执行文件以对话框入口形式自我 spawn——不受任何自动化测试覆盖：源码平面与普通 node 下构建出的 `lib/worker.cjs` 已被覆盖，打包 spawn 推迟到 Windows CI 路线图。