fix(client,doc): address review — flow-open busy gating, seam on the architecture map, browse gap documented

- While a picking flow is open (native chooser pending, browse dialog up) or
  its pick is being adopted, every other menu action disables: a late outcome
  must not race a concurrent selection or creation (ds-review-bot warning).
- ctx.directoryPicker joins the architecture Capability Services map (both
  languages); neighboring rows condensed to keep the doc inside its ceiling.
- directory-picker-browse documents that its client half lands in the next
  stacked PR: a -browse composition today hides the picking affordance (the
  documented empty-hole default) rather than misbehaving (ds-review-bot
  critical; the dialog itself ships in #821).

packages/host/directory-picker-browse/README.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 packages/host/directory-picker-browse/README.md
-README.md: 688a60894cb0ab066a6d501e4df310f8d31bfb5f
-README.zh.md: c19bccc2ff9268cb7a6c931da4671bebc9f76b0c
+README.md: 632dfec3dac57cac9ea7a02225959fe6e3acf6a0
+README.zh.md: 81a1eb53eac0d3b5a1ef8f2f98c4359ef6a4c5fd

packages/host/directory-picker-browse/README.md

@@ -16,6 +16,7 @@ None; this package neither assembles nor sends a provider request.
 
 ## Known Limitations and Deferred Work
 
+- **No client half yet** — the in-app browsing dialog that consumes these primitives lands in the next PR of this stack; until then a `-browse` composition hides the picking affordance entirely (ui-workspace's documented empty-hole default) and the listing/creation RPCs go unconsumed.
 - **Windows hidden attribute is not read** — Node dirents do not expose `FILE_ATTRIBUTE_HIDDEN`, so `hidden` means dot-prefixed on every platform until a native probe is worth its cost.
 - **No drive-root enumeration** — on Windows the ancestry stops at the drive root; crossing drives waits for the browser UI's path-entry affordance rather than an enumeration primitive here.
 - **Whole-filesystem scope** — no per-deployment browse-root restriction; `workspace.create` accepts arbitrary paths today, so a root here would be UX scoping, not a boundary — deferred until a deployment needs it.

packages/host/directory-picker-browse/README.zh.md

@@ -16,6 +16,7 @@
 
 ## 已知限制与延期工作
 
+- **尚无 client half**——消费这些原语的应用内浏览对话框在本栈的下一个 PR 落地；在那之前 `-browse` 组合会完全隐藏选目录入口（ui-workspace 文档化的空洞默认行为），列举／创建 RPC 无消费者。
 - **不读取 Windows 隐藏属性**——Node 的 dirent 不暴露 `FILE_ATTRIBUTE_HIDDEN`，因此在所有平台上 `hidden` 都意味着点前缀，直到原生探测值回其成本为止。
 - **不枚举盘符根**——Windows 上祖先链止于盘符根；跨盘依赖浏览器 UI 的路径输入入口，而不是这里的枚举原语。
 - **全盘可浏览**——没有按部署限定的浏览根；`workspace.create` 今天就接受任意路径，这里的根只会是 UX 范围而非边界——等到有部署需要时再做。