feat(host,client): ship the in-app directory browser as the browse package's client half

directory-picker-browse becomes dual-face: its browser half fills
ui-workspace's two directory-flow holes with the Select Workspace Directory
dialog (figma Harness 813-23126 family — Miller two-column view, breadcrumb
with click-to-edit path zone, nested New-folder dialog), driving the node
half's host.listDirectory/host.createDirectory and owning its locale
namespace (directory-browser, zh default / en). The dialog moves here from
ui-workspace wholesale — the trigger surfaces keep only the flow-hole owner
conversation.

apps/cli flips its one directory-picker row -native -> -browse, swapping the
host backend and the client interaction together; picking now works for
remote deployments out of the box. The keyless workspace-flow snapshot boots
the browse bundle and drives menu -> dialog -> Documents -> project -> Open
against the fixture tree.

packages/host/README.zh.md

@@ -10,6 +10,6 @@ dsh web GUI 的宿主侧：所有客户端形态共用的 API 网关，以及承
 | `webserver/` | 纯 HTTP 路由注册载体：激活即监听的 `node:http` 服务器；路由以命名的 `exact`／`prefix` 处理器注册 | `ctx.httpServer` |
 | `directory-picker/` | 工作区目录选择 seam：网关的 picker RPC 委托的可辨识 `native`／`browse` 能力 | `ctx.directoryPicker` |
 | `directory-picker-native/` | 双面原生交互：OS 选择器后端（osascript／PowerShell／Zenity+KDialog，仅宿主屏幕可用）+ 填入 ui-workspace 目录流 slot 的 browser half | （注册 `ctx.directoryPicker`） |
-| `directory-picker-browse/` | 应用内浏览后端：基于 Node 标准库的列举／创建原语；支持远程 | （注册 `ctx.directoryPicker`） |
+| `directory-picker-browse/` | 双面浏览交互：基于 Node 标准库的列举／创建原语（可远程）+ 渲染应用内选择工作区目录对话框的 browser half | （注册 `ctx.directoryPicker`） |
 
 `apiproxy` 在设计上与传输方式无关——它不注册任何路由；载体自行包装 `ctx.apiProxy`。HTTP 载体路由（连同其 `/api` 浏览器信任栅栏）由 [`client/connection`](../client/connection/README.md) 的 node 半侧挂载，这正是该包住在 client 组的原因：它拥有这条线的两端。