fix(host): drop the folder-dialog Description both picker modes render badly

.NET 10's modern FolderBrowserDialog renders Description as a bottom
strip above the folder input, and the 5.1 classic dialog as an unthemed
white box; the property is dropped entirely and a regression assertion
pins its absence.

.agents/notes/implemented/bug-fix/2026-08-01-windows-picker-pwsh-dpi.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/bug-fix/2026-08-01-windows-picker-pwsh-dpi.md
-2026-08-01-windows-picker-pwsh-dpi.md: 2c90821be3e4800d624cb2f54dcd6661756784bc
-2026-08-01-windows-picker-pwsh-dpi.zh.md: ff8a535af396ed5ede51cbd3c69c1944d28ce95e
+2026-08-01-windows-picker-pwsh-dpi.md: 0ca413f575b5e2805f29b899e638844916e72573
+2026-08-01-windows-picker-pwsh-dpi.zh.md: 6842acfc1e1bd9f3342a2bedb878fe2df40449df

.agents/notes/implemented/bug-fix/2026-08-01-windows-picker-pwsh-dpi.md

@@ -10,7 +10,7 @@ The Windows branch of the native directory picker spawned Windows PowerShell 5.1
 
 ## Decision
 
-The win32 branch in `packages/host/directory-picker-native` now spawns `pwsh.exe` (PowerShell 7) first and falls back to `powershell.exe` (Windows PowerShell 5.1) only when pwsh is missing (`ENOENT`), mirroring the Zenity→KDialog fallback. PowerShell 7's WinForms `FolderBrowserDialog` supports `AutoUpgradeEnabled` (added in .NET Core 3.0, absent from .NET Framework) and renders the modern Explorer-style folder picker. Both runtimes execute the identical script, which calls `SetProcessDPIAware()` (user32) before any window exists, so the dialog is system-DPI-aware no matter which host serves it. `-STA` stays explicit for both, and the fallback keeps the seam's cancellation/failure contract (`null` on cancel, a retryable error otherwise). The host-boundary, RPC trust, and cancellation decisions stay with the [picker feature note](../feature/2026-07-27-native-workspace-directory-picker.md).
+The win32 branch in `packages/host/directory-picker-native` now spawns `pwsh.exe` (PowerShell 7) first and falls back to `powershell.exe` (Windows PowerShell 5.1) only when pwsh is missing (`ENOENT`), mirroring the Zenity→KDialog fallback. PowerShell 7's WinForms `FolderBrowserDialog` supports `AutoUpgradeEnabled` (added in .NET Core 3.0, absent from .NET Framework) and renders the modern Explorer-style folder picker. Both runtimes execute the identical script, which calls `SetProcessDPIAware()` (user32) before any window exists, so the dialog is system-DPI-aware no matter which host serves it. The script sets no `Description`: .NET 10's modern `FolderBrowserDialog` renders it as a bottom strip above the folder input, and the 5.1 classic dialog as an unthemed box, so the property is dropped entirely. `-STA` stays explicit for both, and the fallback keeps the seam's cancellation/failure contract (`null` on cancel, a retryable error otherwise). The host-boundary, RPC trust, and cancellation decisions stay with the [picker feature note](../feature/2026-07-27-native-workspace-directory-picker.md).
 
 ## Alternatives considered
 

.agents/notes/implemented/bug-fix/2026-08-01-windows-picker-pwsh-dpi.zh.md

@@ -10,7 +10,7 @@ Status: implemented
 
 ## 决策
 
-`packages/host/directory-picker-native` 的 win32 分支现在先启动 `pwsh.exe`（PowerShell 7），仅当 pwsh 缺失（`ENOENT`）时才回退到 `powershell.exe`（Windows PowerShell 5.1），与 Zenity→KDialog 的回退方式一致。PowerShell 7 的 WinForms `FolderBrowserDialog` 支持 `AutoUpgradeEnabled`（.NET Core 3.0 加入；.NET Framework 没有），呈现现代资源管理器风格文件夹选择器。两个运行时执行完全相同的脚本，脚本在任何窗口存在前调用 `SetProcessDPIAware()`（user32），因此无论由哪个宿主服务，对话框都系统 DPI aware。两个运行时都显式保留 `-STA`；回退维持 seam 的取消／失败契约（取消返回 `null`，其余为可重试错误）。宿主边界、RPC 信任与取消决策仍归[选择器功能 Note](../feature/2026-07-27-native-workspace-directory-picker.md)所有。
+`packages/host/directory-picker-native` 的 win32 分支现在先启动 `pwsh.exe`（PowerShell 7），仅当 pwsh 缺失（`ENOENT`）时才回退到 `powershell.exe`（Windows PowerShell 5.1），与 Zenity→KDialog 的回退方式一致。PowerShell 7 的 WinForms `FolderBrowserDialog` 支持 `AutoUpgradeEnabled`（.NET Core 3.0 加入；.NET Framework 没有），呈现现代资源管理器风格文件夹选择器。两个运行时执行完全相同的脚本，脚本在任何窗口存在前调用 `SetProcessDPIAware()`（user32），因此无论由哪个宿主服务，对话框都系统 DPI aware。脚本不设置 `Description`：.NET 10 的现代 `FolderBrowserDialog` 会把它渲染成文件夹输入框上方的一条底带，5.1 经典对话框则渲染成未主题化的色块，因此该属性被整体移除。两个运行时都显式保留 `-STA`；回退维持 seam 的取消／失败契约（取消返回 `null`，其余为可重试错误）。宿主边界、RPC 信任与取消决策仍归[选择器功能 Note](../feature/2026-07-27-native-workspace-directory-picker.md)所有。
 
 ## 考虑过的替代方案
 

packages/host/directory-picker-native/src/native-picker.ts

@@ -68,14 +68,15 @@ export async function pickNativeDirectory(
     // PowerShell 5.1's FolderBrowserDialog is hardwired to the legacy
     // SHBrowseForFolder tree; prefer pwsh and fall back only when it is absent.
     // Both hosts spawn DPI-unaware, so the script opts the process into system
-    // DPI awareness before any window is created.
+    // DPI awareness before any window is created. No Description is set: the
+    // modern dialog renders it as a bottom strip and the classic dialog as an
+    // unthemed box.
     const script = [
       "$ErrorActionPreference = 'Stop'",
       "Add-Type -TypeDefinition 'using System; using System.Runtime.InteropServices; public static class DpiAware { [DllImport(\"user32.dll\")] public static extern bool SetProcessDPIAware(); }'",
       '[DpiAware]::SetProcessDPIAware() | Out-Null',
       'Add-Type -AssemblyName System.Windows.Forms',
       '$dialog = New-Object System.Windows.Forms.FolderBrowserDialog',
-      "$dialog.Description = 'Select Workspace Directory'",
       '$dialog.ShowNewFolderButton = $true',
       '$result = $dialog.ShowDialog()',
       'if ($result -eq [System.Windows.Forms.DialogResult]::OK) {',

packages/host/directory-picker-native/tests/native-picker.spec.ts

@@ -57,6 +57,8 @@ describe('native directory picker', () => {
     const script = run.mock.calls[0]?.[1].at(-1)
     expect(script).toContain("$ErrorActionPreference = 'Stop'")
     expect(script).toContain('SetProcessDPIAware')
+    // Description renders as a bottom strip (modern) / unthemed box (classic); never set it.
+    expect(script).not.toContain('Description')
     run.mockResolvedValueOnce({ stdout: '', stderr: '' })
     await expect(pickNativeDirectory(signal(), { platform: 'win32', run })).resolves.toBeNull()
     run.mockRejectedValueOnce(failure(1, 'Add-Type failed'))