feat(host): adaptive directory-picker default via -auto chooser

Add @deepseek-ai/dsh-host-directory-picker-auto, a node-half-only chooser that samples the host situation once at boot (bind host via a new httpServer.host getter, SSH markers, platform, DISPLAY/WAYLAND_DISPLAY) and mounts the matching dual-face backend (-native or -browse) as a real Loader entry in the in-memory root tree; the effect disposer removes it. Entry-level mounting keeps the seam's one-row-swaps-both-faces invariant: the client module table discovers the mounted backend's browser half exactly as a config row's. apps/cli now composes -auto as its directory-picker row; composing a backend row directly remains the pin.
2026-07-29 18:34:06 +08:00
parent 87c9ab06b3
commit 8cec74748b
32 changed files with 553 additions and 19 deletions
--- a/packages/host/README.i18n.yaml
+++ b/packages/host/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/README.md
-README.md: d44770f70be16c12f44b78155089e092a3e9bba0
-README.zh.md: 2b6878b08be6489dcd510a0a0e0f0e833c2a8014
+README.md: 4f56afc45d594bf1f3f0784b848958cf62f52ae5
+README.zh.md: 888301282e272966b9d99e299b893afc90670906
--- a/packages/host/README.md
+++ b/packages/host/README.md
@@ -11,5 +11,6 @@ The host side of the dsh web GUI: the API gateway every client shape shares, and
 | `directory-picker/` | Workspace-directory picking seam: discriminated `native`/`browse` capability the gateway's picker RPCs delegate to | `ctx.directoryPicker` |
 | `directory-picker-native/` | Dual-face native interaction: OS-chooser backend (osascript / PowerShell / Zenity+KDialog, host-display only) + the browser half filling ui-workspace's directory-flow slots | (registers `ctx.directoryPicker`) |
 | `directory-picker-browse/` | Dual-face browse interaction: listing/creation primitives over Node stdlib (remote-capable) + the browser half rendering the in-app Select Workspace Directory dialog | (registers `ctx.directoryPicker`) |
+| `directory-picker-auto/` | Adaptive chooser: resolves the host's situation once at boot (bind host, SSH, display) and mounts the matching dual-face backend as an in-memory Loader entry | (mounts a backend row) |

 `apiproxy` is transport-agnostic by design — it registers no routes; carriers wrap `ctx.apiProxy` themselves. The HTTP carrier route (with its `/api` browser-trust fence) is mounted by [`client/connection`](../client/connection/README.md)'s node half, which is why that package lives in the client group: it owns both ends of the wire.
--- a/packages/host/README.zh.md
+++ b/packages/host/README.zh.md
@@ -11,5 +11,6 @@ dsh web GUI 的宿主侧：所有客户端形态共用的 API 网关，以及承
 | `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/` | 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`） |
+| `directory-picker-auto/` | 自适应选择器：启动时一次性判定宿主处境（绑定宿主、SSH、显示），并把匹配的双面后端挂载为内存中的 Loader 条目 | （挂载一个后端行） |

 `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。
--- a/packages/host/directory-picker-auto/README.i18n.yaml
+++ b/packages/host/directory-picker-auto/README.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 packages/host/directory-picker-auto/README.md
+README.md: 73692d1fb5af1e7b23b2a99d0a5cd48507f68ce5
+README.zh.md: 5bc9ced01f86d021db256df2c9e69e97ec6a7ab1
--- a/packages/host/directory-picker-auto/README.md
+++ b/packages/host/directory-picker-auto/README.md
@@ -0,0 +1,20 @@
+# @deepseek-ai/dsh-host-directory-picker-auto
+
+English | [中文](README.zh.md)
+
+The **adaptive chooser** of the [directory-picker seam](../directory-picker/README.md): a node-half-only plugin that resolves the host's situation once at boot and mounts the matching dual-face backend — [`-native`](../directory-picker-native/README.md) or [`-browse`](../directory-picker-browse/README.md) — as a real Loader entry in the in-memory root tree (never persisted to a config file; the root tree's `write()` is a no-op). Because the backend arrives as an ordinary entry, its browser half is discovered by the client module table exactly as a config-row's would be, so the seam's one-row-swaps-both-faces invariant holds for the resolved choice. Unloading the chooser removes the entry again, unloading both faces with it.
+
+Resolution is one pure boot-time sample (`resolveDirectoryPickerBackend`), exported for reuse and tests. `native` requires every signal that the operator can see the host display: a loopback-only bind (read from the injected `httpServer`; an all-interfaces bind admits remote browsers no OS chooser can reach), no SSH launch (`SSH_CONNECTION`/`SSH_TTY` unset or blank — under SSH port-forwarding the chooser would open on the unattended server), and a display session (assumed on darwin/win32; `DISPLAY`/`WAYLAND_DISPLAY` elsewhere). Anything ambiguous resolves to `browse`, which works everywhere. The sample happens exactly once per boot so the mounted capability stays stable for the service lifetime, as the seam requires. Pinning an interaction is not a config field here — compose the `-native` or `-browse` row directly instead of this one, the seam's documented swap point; mounting the chooser **and** a backend row together fails loud (duplicate `directoryPicker` service, duplicate client flow in the `single` holes).
+
+## Model Experience
+
+None, as the chooser only composes the GUI host's directory selection; nothing here reaches a model request.
+
+#### KV Cache effect
+
+None; this package neither assembles nor sends a provider request.
+
+## Known Limitations and Deferred Work
+
+- **Detection is a heuristic, not a proof** — a tmux session detached from its SSH launch loses the `SSH_*` markers, and a darwin process outside an Aqua session still counts as displayed; a wrong `native` choice degrades to the backend's existing retryable failure dialog, and composing `-browse` directly pins the safe interaction.
+- **Boot-time only** — one resolution serves every client of the boot; per-connection adaptivity (native for a local browser, browse for a remote one, same server) would need a per-client capability and the wire advertisement the seam deliberately deleted, and waits for a deployment that serves both at once.
--- a/packages/host/directory-picker-auto/README.zh.md
+++ b/packages/host/directory-picker-auto/README.zh.md
@@ -0,0 +1,20 @@
+# @deepseek-ai/dsh-host-directory-picker-auto
+
+[English](README.md) | 中文
+
+[目录选择 seam](../directory-picker/README.md) 的**自适应选择器**：一个只有 node 半侧的插件，在启动时一次性判定宿主处境，并把匹配的双面后端——[`-native`](../directory-picker-native/README.md) 或 [`-browse`](../directory-picker-browse/README.md)——作为真实的 Loader 条目挂进内存根树（绝不持久化到配置文件；根树的 `write()` 是 no-op）。由于后端以普通条目的形式到达，其 browser half 被 client 模块表发现的方式与配置行完全相同，因此对判定出的选择，seam 的“一行同时换两面”不变式依然成立。卸载该选择器会再次移除该条目，连同两面一起卸载。
+
+判定是一次纯函数的启动时采样（`resolveDirectoryPickerBackend`），已导出供复用与测试。`native` 要求“操作者看得到宿主屏幕”的全部信号：仅回环的绑定（从注入的 `httpServer` 读取；全网卡绑定会接入任何 OS 选择器都触及不到的远程浏览器）；非 SSH 启动（`SSH_CONNECTION`／`SSH_TTY` 未设置或为空——SSH 端口转发下选择器会弹在无人值守的服务器上）；以及存在显示会话（darwin／win32 上视为存在，其余平台看 `DISPLAY`／`WAYLAND_DISPLAY`）。任何含糊情形都判定为处处可用的 `browse`。采样每次启动恰好发生一次，因此挂载的能力在服务生命周期内保持稳定，符合 seam 的要求。固定某种交互在这里不是配置字段——直接组合 `-native` 或 `-browse` 行来替代本行，那才是 seam 文档化的切换点；同时挂载选择器**和**某个后端行会大声失败（重复的 `directoryPicker` 服务、`single` 洞中的重复 client 流程）。
+
+## 模型体验
+
+无。该选择器仅组合 GUI 宿主的目录选择；这里没有任何内容进入模型请求。
+
+#### KV 缓存影响
+
+无；该包既不组装也不发送提供方请求。
+
+## 已知限制与延期工作
+
+- **探测是启发式，不是证明**——从 SSH 启动中脱离的 tmux 会话会丢失 `SSH_*` 标记，Aqua 会话之外的 darwin 进程也仍被算作有显示；错误的 `native` 选择会退化为后端既有的可重试失败对话框，而直接组合 `-browse` 即固定住安全的交互。
+- **仅在启动时判定**——一次判定服务本次启动的所有客户端；按连接自适应（同一台服务器，本地浏览器用 native、远程浏览器用 browse）需要按客户端的能力对象以及 seam 有意删除的 wire 广播，等到出现同时服务两种形态的部署再做。
--- a/packages/host/directory-picker-auto/package.json
+++ b/packages/host/directory-picker-auto/package.json
@@ -0,0 +1,47 @@
+{
+  "name": "@deepseek-ai/dsh-host-directory-picker-auto",
+  "description": "Adaptive chooser of the directory-picker seam: resolves the host situation at boot and mounts the native or browse backend for the DeepSeek Harness web GUI host",
+  "version": "0.0.1",
+  "private": true,
+  "type": "module",
+  "main": "lib/index.js",
+  "types": "lib/types/index.d.ts",
+  "exports": {
+    ".": {
+      "types": "./lib/types/index.d.ts",
+      "default": "./lib/index.js"
+    },
+    "./invariant": {
+      "types": "./lib/types/invariant.d.ts",
+      "default": "./lib/invariant.js"
+    },
+    "./src/*": "./src/*",
+    "./package.json": "./package.json"
+  },
+  "files": [
+    "lib/index.js",
+    "lib/invariant.js",
+    "lib/types/**/*.d.ts",
+    "lib/types/**/*.d.ts.map",
+    "src"
+  ],
+  "license": "BSD-3-Clause",
+  "peerDependencies": {
+    "@cordisjs/plugin-loader": "^1.0.0-rc.5",
+    "@deepseek-ai/dsh-host-directory-picker-browse": "^0.0.1",
+    "@deepseek-ai/dsh-host-directory-picker-native": "^0.0.1",
+    "@deepseek-ai/dsh-host-webserver": "^0.0.1",
+    "@deepseek-ai/dsh-invariants": "^0.0.1",
+    "cordis": "^4.0.0-rc.7"
+  },
+  "devDependencies": {
+    "@cordisjs/plugin-include": "workspace:^",
+    "@cordisjs/plugin-loader": "workspace:^",
+    "@deepseek-ai/dsh-host-directory-picker": "workspace:^",
+    "@deepseek-ai/dsh-host-directory-picker-browse": "workspace:^",
+    "@deepseek-ai/dsh-host-directory-picker-native": "workspace:^",
+    "@deepseek-ai/dsh-host-webserver": "workspace:^",
+    "@deepseek-ai/dsh-invariants": "workspace:^",
+    "cordis": "^4.0.0-rc.7"
+  }
+}
--- a/packages/host/directory-picker-auto/src/index.ts
+++ b/packages/host/directory-picker-auto/src/index.ts
@@ -0,0 +1,52 @@
+/**
+ * Adaptive chooser of the directory-picker seam: resolves the host's
+ * situation once at boot (bind host, SSH launch, display session) and mounts
+ * the matching dual-face backend — `-native` or `-browse` — as a real Loader
+ * entry in the in-memory root tree. Because the backend arrives as an
+ * ordinary entry, its browser half is discovered exactly as a config-row's
+ * would be, so the seam's one-row-swaps-both-faces invariant holds for the
+ * resolved choice; pinning an interaction remains composing that backend row
+ * directly instead of this one.
+ * @module @deepseek-ai/dsh-host-directory-picker-auto
+ */
+
+import type { Context } from 'cordis'
+// Empty type imports carry the `loader` and `httpServer` Context merges for the reads below.
+import type {} from '@cordisjs/plugin-loader'
+import type {} from '@deepseek-ai/dsh-host-webserver'
+import type { DirectoryPickerBackendKind } from './resolve.ts'
+import { resolveDirectoryPickerBackend } from './resolve.ts'
+
+export type { DirectoryPickerBackendKind, DirectoryPickerEnv, DirectoryPickerHostFacts } from './resolve.ts'
+export { resolveDirectoryPickerBackend } from './resolve.ts'
+
+/** Cordis plugin name. */
+export const name = 'directory-picker-auto'
+/** Required services: the effective bind host (`httpServer`) and the entry tree the backend mounts into (`loader`). */
+export const inject = ['httpServer', 'loader']
+
+/** Backend package per resolved kind — fixed composition vocabulary, not a tunable. */
+const BACKEND_PACKAGES: Record<DirectoryPickerBackendKind, string> = {
+  native: '@deepseek-ai/dsh-host-directory-picker-native',
+  browse: '@deepseek-ai/dsh-host-directory-picker-browse',
+}
+
+/**
+ * Resolve the backend from one boot-time sample and mount it as a Loader
+ * entry; the effect's disposer removes the entry, so unloading this plugin
+ * unloads both faces of the mounted backend with it.
+ * @param ctx - cordis context carrying the injected `httpServer` and `loader`.
+ */
+export async function apply(ctx: Context): Promise<void> {
+  const backend = resolveDirectoryPickerBackend({
+    bindHost: ctx.httpServer.host,
+    platform: process.platform,
+    env: process.env,
+  })
+  await ctx.effect(async () => {
+    // Root-tree create: the Loader root is in-memory (write() is a no-op), so
+    // the mounted row can never be persisted back into a config file.
+    const id = await ctx.loader.create({ name: BACKEND_PACKAGES[backend] })
+    return () => { ctx.loader.remove(id) }
+  }, 'directory-picker-auto: backend entry')
+}
--- a/packages/host/directory-picker-auto/src/invariant.ts
+++ b/packages/host/directory-picker-auto/src/invariant.ts
@@ -0,0 +1,25 @@
+/**
+ * Package-owned invariant companion for the adaptive directory-picker chooser.
+ * @module @deepseek-ai/dsh-host-directory-picker-auto/invariant
+ */
+
+import type { Context } from 'cordis'
+import type { InvariantInstaller } from '@deepseek-ai/dsh-invariants'
+
+const PACKAGE_NAME = '@deepseek-ai/dsh-host-directory-picker-auto'
+
+/** Cordis companion plugin name. */
+export const name = 'host-directory-picker-auto-invariant'
+/** Service required before the companion can reserve package ownership. */
+export const inject = ['invariants']
+
+/** No runtime invariant: the sole effect is one boot-time Loader-entry mount owned by the plugin fiber; the store is authoritative. */
+const install: InvariantInstaller = () => {}
+
+/**
+ * Register the adaptive directory-picker invariant companion.
+ * @param ctx - Cordis context carrying the invariant service.
+ * @returns the installed registration's disposer after setup succeeds.
+ */
+export const apply = (ctx: Context): Promise<() => void> =>
+  Promise.resolve(ctx.invariants.register(PACKAGE_NAME, install))
--- a/packages/host/directory-picker-auto/src/resolve.ts
+++ b/packages/host/directory-picker-auto/src/resolve.ts
@@ -0,0 +1,46 @@
+/**
+ * Boot-time backend resolution for the adaptive directory-picker composition:
+ * one pure decision from sampled host facts to a concrete backend kind. The
+ * caller samples exactly once per boot, so the mounted capability stays
+ * stable for the service lifetime as the seam requires.
+ * @module @deepseek-ai/dsh-host-directory-picker-auto/resolve
+ */
+
+/** Concrete interaction backend the resolver chooses between. */
+export type DirectoryPickerBackendKind = 'native' | 'browse'
+
+/** Environment keys the resolution reads (a `process.env` subset). */
+export type DirectoryPickerEnv = Readonly<
+  Partial<Record<'SSH_CONNECTION' | 'SSH_TTY' | 'DISPLAY' | 'WAYLAND_DISPLAY', string>>
+>
+
+/** Host facts the backend choice is a pure function of, sampled once at boot. */
+export interface DirectoryPickerHostFacts {
+  /** Effective webserver bind host (`127.0.0.1` or `0.0.0.0`). */
+  bindHost: string
+  /** Host process platform. */
+  platform: NodeJS.Platform
+  /** Environment sample; SSH marks a remote operator, DISPLAY/WAYLAND_DISPLAY a Linux display. */
+  env: DirectoryPickerEnv
+}
+
+/** An env value counts only when set and non-blank (an empty export is "unset" by shell convention). */
+const present = (value: string | undefined): boolean => value !== undefined && value !== ''
+
+/**
+ * Resolve which backend serves this boot. `native` requires every signal that
+ * the operator can see the host display: a loopback-only bind (an
+ * all-interfaces bind admits remote browsers no OS chooser can reach), no SSH
+ * launch (under SSH port-forwarding the chooser would open on the unattended
+ * server), and a display session (assumed on darwin/win32, `DISPLAY`/
+ * `WAYLAND_DISPLAY` elsewhere). Anything ambiguous resolves to `browse`,
+ * which works everywhere.
+ * @param facts - the sampled host facts.
+ * @returns the backend kind to mount.
+ */
+export function resolveDirectoryPickerBackend(facts: DirectoryPickerHostFacts): DirectoryPickerBackendKind {
+  if (facts.bindHost !== '127.0.0.1') return 'browse'
+  if (present(facts.env.SSH_CONNECTION) || present(facts.env.SSH_TTY)) return 'browse'
+  if (facts.platform === 'darwin' || facts.platform === 'win32') return 'native'
+  return present(facts.env.DISPLAY) || present(facts.env.WAYLAND_DISPLAY) ? 'native' : 'browse'
+}
--- a/packages/host/directory-picker-auto/tests/loader-composition.spec.ts
+++ b/packages/host/directory-picker-auto/tests/loader-composition.spec.ts
@@ -0,0 +1,139 @@
+/**
+ * REAL-composition coverage: a test-only cordis.yml booted through the
+ * vendored Loader mounts the webserver row plus the adaptive chooser, and the
+ * assertions observe the durable outcome — which backend entry the chooser
+ * mounted into the Loader store, the capability the seam then serves, and
+ * that disposing the chooser removes the mounted entry again (HMR safety).
+ */
+
+import { mkdir, mkdtemp, readFile, rm, writeFile } from 'node:fs/promises'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+import { pathToFileURL } from 'node:url'
+import { afterEach, describe, expect, it, vi } from 'vitest'
+import { Context } from 'cordis'
+import Loader from '@cordisjs/plugin-loader'
+import Include from '@cordisjs/plugin-include'
+import HttpServer from '@deepseek-ai/dsh-host-webserver'
+import type { DirectoryPicker } from '@deepseek-ai/dsh-host-directory-picker'
+import BrowseDirectoryPicker from '@deepseek-ai/dsh-host-directory-picker-browse'
+import NativeDirectoryPicker from '@deepseek-ai/dsh-host-directory-picker-native'
+import * as DirectoryPickerAuto from '../src/index.ts'
+
+const AUTO = '@deepseek-ai/dsh-host-directory-picker-auto'
+const NATIVE = '@deepseek-ai/dsh-host-directory-picker-native'
+const BROWSE = '@deepseek-ai/dsh-host-directory-picker-browse'
+
+let root: string | undefined
+let context: Context | undefined
+
+afterEach(async () => {
+  vi.unstubAllEnvs()
+  await context?.fiber.dispose()
+  context = undefined
+  if (root !== undefined) await rm(root, { recursive: true, force: true })
+  root = undefined
+})
+
+/** Write a dist fixture and a two-row cordis.yml (webserver + chooser), then boot it through the real Loader. */
+async function loadComposition(bindHost: '127.0.0.1' | '0.0.0.0'): Promise<{ ctx: Context; configPath: string }> {
+  root = await mkdtemp(join(tmpdir(), 'dsh-directory-picker-auto-'))
+  const dist = join(root, 'dist')
+  await mkdir(dist)
+  const distIndex = join(dist, 'index.html')
+  await writeFile(distIndex, '<head></head><body>shell</body>')
+  const configPath = join(root, 'cordis.yml')
+  await writeFile(configPath, [
+    "- name: '@deepseek-ai/dsh-host-webserver'",
+    '  config:',
+    `    host: '${bindHost}'`,
+    '    port: 0',
+    `    distIndex: '${distIndex}'`,
+    `- name: '${AUTO}'`,
+    '',
+  ].join('\n'))
+
+  context = new Context()
+  context.baseUrl = pathToFileURL(root).href + '/'
+  await context.plugin(Loader)
+  context.loader.builtins.include = Include
+  const modules = new Map<string, unknown>([
+    ['@deepseek-ai/dsh-host-webserver', HttpServer],
+    [AUTO, DirectoryPickerAuto],
+    [NATIVE, NativeDirectoryPicker],
+    [BROWSE, BrowseDirectoryPicker],
+  ])
+  context.loader.internal = {
+    version: 'v2',
+    async import(specifier: string) {
+      if (!modules.has(specifier)) throw new Error(`unexpected Loader import: ${specifier}`)
+      return modules.get(specifier)
+    },
+  } as unknown as NonNullable<typeof context.loader.internal>
+  await context.loader.create({
+    name: 'cordis:include',
+    config: { path: pathToFileURL(configPath).href },
+  })
+  await context.loader.await()
+  return { ctx: context, configPath }
+}
+
+/** Entry names currently present in the loader store (root tree plus subtrees). */
+function entryNames(ctx: Context): string[] {
+  return [...ctx.loader.entries()].map(entry => entry.options.name)
+}
+
+/** Force every signal of an attended host: no SSH launch, a display on any platform. */
+function stubAttendedHost(): void {
+  vi.stubEnv('SSH_CONNECTION', '')
+  vi.stubEnv('SSH_TTY', '')
+  vi.stubEnv('DISPLAY', ':0')
+}
+
+describe('real Loader composition', () => {
+  // Real-Loader composition resolves workspace packages through tsx at test
+  // time; first resolution after the host/client program split is slow enough
+  // to trip the default 5s budget on cold caches.
+  it('mounts the native backend for an attended loopback host and unmounts it on disposal', { timeout: 60_000 }, async () => {
+    stubAttendedHost()
+    const { ctx, configPath } = await loadComposition('127.0.0.1')
+
+    const unloaded = [...ctx.loader.entries()]
+      .filter(entry => entry.fiber === undefined && !entry.disabled)
+      .map(entry => entry.options.name)
+    expect(unloaded).toEqual([])
+    expect(entryNames(ctx)).toContain(NATIVE)
+    expect(entryNames(ctx)).not.toContain(BROWSE)
+    const picker = ctx.get('directoryPicker') as DirectoryPicker
+    expect(picker.capability().kind).toBe('native')
+    // The mounted row lives in the Loader's in-memory root tree only — the
+    // booted config file must never gain the resolved backend row.
+    expect(await readFile(configPath, 'utf8')).not.toContain(NATIVE)
+
+    // HMR safety: disposing the chooser's fiber removes the entry it created.
+    const autoEntry = [...ctx.loader.entries()].find(entry => entry.options.name === AUTO)!
+    await autoEntry.fiber!.dispose()
+    await ctx.loader.await()
+    expect(entryNames(ctx)).not.toContain(NATIVE)
+    expect(ctx.get('directoryPicker')).toBeUndefined()
+  })
+
+  it('mounts the browse backend under an SSH launch', { timeout: 60_000 }, async () => {
+    stubAttendedHost()
+    vi.stubEnv('SSH_CONNECTION', '10.0.0.2 55 10.0.0.9 22')
+    const { ctx } = await loadComposition('127.0.0.1')
+
+    expect(entryNames(ctx)).toContain(BROWSE)
+    expect(entryNames(ctx)).not.toContain(NATIVE)
+    const picker = ctx.get('directoryPicker') as DirectoryPicker
+    expect(picker.capability().kind).toBe('browse')
+  })
+
+  it('mounts the browse backend for an all-interfaces bind even on an attended host', { timeout: 60_000 }, async () => {
+    stubAttendedHost()
+    const { ctx } = await loadComposition('0.0.0.0')
+
+    expect(entryNames(ctx)).toContain(BROWSE)
+    expect(entryNames(ctx)).not.toContain(NATIVE)
+  })
+})
--- a/packages/host/directory-picker-auto/tests/resolve.spec.ts
+++ b/packages/host/directory-picker-auto/tests/resolve.spec.ts
@@ -0,0 +1,37 @@
+import { describe, expect, it } from 'vitest'
+import { resolveDirectoryPickerBackend } from '../src/resolve.ts'
+import type { DirectoryPickerHostFacts } from '../src/resolve.ts'
+
+/** Baseline facts that resolve to `native`; each case overrides one signal. */
+const attended: DirectoryPickerHostFacts = {
+  bindHost: '127.0.0.1',
+  platform: 'darwin',
+  env: {},
+}
+
+describe('resolveDirectoryPickerBackend', () => {
+  it('resolves native for a loopback bind on a display platform', () => {
+    expect(resolveDirectoryPickerBackend(attended)).toBe('native')
+    expect(resolveDirectoryPickerBackend({ ...attended, platform: 'win32' })).toBe('native')
+  })
+
+  it('resolves browse for an all-interfaces bind regardless of other signals', () => {
+    expect(resolveDirectoryPickerBackend({ ...attended, bindHost: '0.0.0.0' })).toBe('browse')
+  })
+
+  it('resolves browse under an SSH launch (either env marker)', () => {
+    expect(resolveDirectoryPickerBackend({ ...attended, env: { SSH_CONNECTION: '10.0.0.2 55 10.0.0.9 22' } })).toBe('browse')
+    expect(resolveDirectoryPickerBackend({ ...attended, env: { SSH_TTY: '/dev/pts/3' } })).toBe('browse')
+  })
+
+  it('requires a display session on platforms without an implied one', () => {
+    expect(resolveDirectoryPickerBackend({ ...attended, platform: 'linux' })).toBe('browse')
+    expect(resolveDirectoryPickerBackend({ ...attended, platform: 'linux', env: { DISPLAY: ':0' } })).toBe('native')
+    expect(resolveDirectoryPickerBackend({ ...attended, platform: 'linux', env: { WAYLAND_DISPLAY: 'wayland-1' } })).toBe('native')
+  })
+
+  it('treats blank env exports as unset', () => {
+    expect(resolveDirectoryPickerBackend({ ...attended, env: { SSH_CONNECTION: '', SSH_TTY: '' } })).toBe('native')
+    expect(resolveDirectoryPickerBackend({ ...attended, platform: 'linux', env: { DISPLAY: '', WAYLAND_DISPLAY: '' } })).toBe('browse')
+  })
+})
--- a/packages/host/directory-picker-auto/tsconfig.json
+++ b/packages/host/directory-picker-auto/tsconfig.json
@@ -0,0 +1,27 @@
+{
+  "extends": "../../../tsconfig.base.json",
+  "compilerOptions": {
+    "rootDir": "src",
+    "outDir": "lib/types"
+  },
+  "include": [
+    "src"
+  ],
+  "references": [
+    {
+      "path": "../../../vendor/cosmokit"
+    },
+    {
+      "path": "../../../vendor/cordis"
+    },
+    {
+      "path": "../../../vendor/loader"
+    },
+    {
+      "path": "../webserver"
+    },
+    {
+      "path": "../../support/invariants"
+    }
+  ]
+}
--- a/packages/host/directory-picker/README.i18n.yaml
+++ b/packages/host/directory-picker/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/README.md
-README.md: 8ef8889c875f5b1d07c015ddef819591041c8d7f
-README.zh.md: 8aefffa7b29a47205ea42d0d1df742d1e1b2502d
+README.md: 3749b238b56578ec68610bc13550760aa084bad6
+README.zh.md: 488da5129ec211c2a064156c22a9d0abf04d99be
--- a/packages/host/directory-picker/README.md
+++ b/packages/host/directory-picker/README.md
@@ -2,7 +2,7 @@

 English | [中文](README.zh.md)

-The **workspace-directory picking seam** for the web-GUI host: an abstract `DirectoryPicker` service (`ctx.directoryPicker`) whose single contract method `capability()` returns a discriminated capability describing how an operator selects a directory. Backends differ in interaction shape, not just mechanism, so the seam models the shapes explicitly instead of one method set: `{ kind: 'native', pick(signal) }` opens one native OS chooser on the host display ([`-native`](../directory-picker-native/README.md)); `{ kind: 'browse', list(path?), createDirectory(path, name) }` serves listing/creation primitives an in-app browser drives, which works for remote clients no OS chooser can reach ([`-browse`](../directory-picker-browse/README.md)). Consumers switch on `capability().kind`; the union derives from the merge-extensible `DirectoryPickerCapabilities` map (a new backend declaration-merges its shape there), and the documented default for an unknown kind is to hide the picking affordance rather than fail. The capability object must be stable for the service lifetime. The client side mirrors the seam without a wire advertisement: each backend package is dual-face, its browser half registering the matching picking interaction into ui-workspace's directory-flow slots — so one composition row swaps both the host capability and the client flow together.
+The **workspace-directory picking seam** for the web-GUI host: an abstract `DirectoryPicker` service (`ctx.directoryPicker`) whose single contract method `capability()` returns a discriminated capability describing how an operator selects a directory. Backends differ in interaction shape, not just mechanism, so the seam models the shapes explicitly instead of one method set: `{ kind: 'native', pick(signal) }` opens one native OS chooser on the host display ([`-native`](../directory-picker-native/README.md)); `{ kind: 'browse', list(path?), createDirectory(path, name) }` serves listing/creation primitives an in-app browser drives, which works for remote clients no OS chooser can reach ([`-browse`](../directory-picker-browse/README.md)). Consumers switch on `capability().kind`; the union derives from the merge-extensible `DirectoryPickerCapabilities` map (a new backend declaration-merges its shape there), and the documented default for an unknown kind is to hide the picking affordance rather than fail. The capability object must be stable for the service lifetime. The client side mirrors the seam without a wire advertisement: each backend package is dual-face, its browser half registering the matching picking interaction into ui-workspace's directory-flow slots — so one composition row swaps both the host capability and the client flow together. A composition that should not pin an interaction mounts the [`-auto`](../directory-picker-auto/README.md) chooser instead, which resolves the host's situation once at boot and mounts the matching backend row itself.

 Browse primitives fail with the typed `DirectoryPickerError` (`directory-unreadable` / `directory-exists` / `directory-create-failed`, each carrying the subject `path`), which the consuming gateway maps 1:1 onto wire error codes. `DirectoryEntry` rows carry a host-owned `hidden` flag (POSIX dot convention) so display policy stays client-side; `DirectoryListing.crumbs` is the ancestor chain from the filesystem root, every crumb a jump target. Design rationale, the `ctx.fs` separation, and the policy decisions live in [the directory-picker capability seam Agent Note](../../../.agents/notes/implemented/architecture/2026-07-28-directory-picker-capability-seam.md).

--- a/packages/host/directory-picker/README.zh.md
+++ b/packages/host/directory-picker/README.zh.md
@@ -2,7 +2,7 @@

 [English](README.md) | 中文

-web GUI 宿主的**工作区目录选择 seam**：抽象服务 `DirectoryPicker`（`ctx.directoryPicker`），唯一契约方法 `capability()` 返回一个可辨识能力对象，描述操作者以何种方式选择目录。后端之间的差异在交互形态而不只是机制，因此 seam 显式建模形态而非统一方法集：`{ kind: 'native', pick(signal) }` 在宿主屏幕上打开一个原生 OS 选择器（[`-native`](../directory-picker-native/README.md)）；`{ kind: 'browse', list(path?), createDirectory(path, name) }` 提供应用内浏览器驱动的列举／创建原语，可服务任何 OS 对话框都触及不到的远程客户端（[`-browse`](../directory-picker-browse/README.md)）。消费方按 `capability().kind` 分支；联合类型由可合并扩展的 `DirectoryPickerCapabilities` 映射派生（新后端在其中声明合并自己的形态），未知 kind 的文档化默认行为是隐藏选择入口而非失败。能力对象在服务生命周期内必须保持稳定。client 侧以镜像方式承接该 seam 而不经 wire 广播：每个后端包都是双面包，其 browser half 把匹配的选取交互注册进 ui-workspace 的目录流 slot——因此一行组合同时切换宿主能力与 client 流程。
+web GUI 宿主的**工作区目录选择 seam**：抽象服务 `DirectoryPicker`（`ctx.directoryPicker`），唯一契约方法 `capability()` 返回一个可辨识能力对象，描述操作者以何种方式选择目录。后端之间的差异在交互形态而不只是机制，因此 seam 显式建模形态而非统一方法集：`{ kind: 'native', pick(signal) }` 在宿主屏幕上打开一个原生 OS 选择器（[`-native`](../directory-picker-native/README.md)）；`{ kind: 'browse', list(path?), createDirectory(path, name) }` 提供应用内浏览器驱动的列举／创建原语，可服务任何 OS 对话框都触及不到的远程客户端（[`-browse`](../directory-picker-browse/README.md)）。消费方按 `capability().kind` 分支；联合类型由可合并扩展的 `DirectoryPickerCapabilities` 映射派生（新后端在其中声明合并自己的形态），未知 kind 的文档化默认行为是隐藏选择入口而非失败。能力对象在服务生命周期内必须保持稳定。client 侧以镜像方式承接该 seam 而不经 wire 广播：每个后端包都是双面包，其 browser half 把匹配的选取交互注册进 ui-workspace 的目录流 slot——因此一行组合同时切换宿主能力与 client 流程。不应固定某种交互的组合改为挂载 [`-auto`](../directory-picker-auto/README.md) 选择器，它在启动时一次性判定宿主处境，并自行挂载匹配的后端行。

 浏览原语以带类型的 `DirectoryPickerError` 失败（`directory-unreadable`／`directory-exists`／`directory-create-failed`，各自携带主体 `path`），消费网关将其 1:1 映射为协议错误码。`DirectoryEntry` 行携带宿主判定的 `hidden` 标志（POSIX 点前缀约定），展示策略留在客户端；`DirectoryListing.crumbs` 是从文件系统根开始的祖先链，每个 crumb 都是跳转目标。设计依据、与 `ctx.fs` 的切分、策略裁决见[目录选择能力 seam Agent Note](../../../.agents/notes/implemented/architecture/2026-07-28-directory-picker-capability-seam.md)。

--- a/packages/host/webserver/README.i18n.yaml
+++ b/packages/host/webserver/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/webserver/README.md
-README.md: e715e4452ddb808f36e6b097eee0fda7b8d0bfb0
-README.zh.md: 05e7e10d7815c8f26bb90597b38b7c6b83a86dbc
+README.md: ace8c09e43dd8544a28d300f97b04610be78bc69
+README.zh.md: b9948e3d387a5da393ff62b9eeacfe310516f46a
--- a/packages/host/webserver/README.md
+++ b/packages/host/webserver/README.md
@@ -2,7 +2,7 @@

 English | [中文](README.zh.md)

-Plain HTTP route-registration plugin (default-exported `HttpServerService`, config `{host, port, distIndex}`): a `node:http` server that listens on activation and provides `ctx.httpServer` — `register(route)` adds a named `exact`/`prefix` route (duplicate `(kind, path)` throws: route patterns are a composition-level contract, so a collision is a misconfiguration; the returned disposer removes the route), `tapIndex(transform)` adds an index.html transform applied in registration order, and `port` reads the listening port (the OS-assigned value when `port` is 0). The match order is fixed — exact over the whole table, then longest prefix, then the static dist fallback with the locked semantics: traversal outside the dist root is 403, any miss falls back to `index.html` with HTTP 200 (SPA routing), unknown extensions ship as octet-stream, non-GET/HEAD is 405. Registration order carries no request-facing semantics.
+Plain HTTP route-registration plugin (default-exported `HttpServerService`, config `{host, port, distIndex}`): a `node:http` server that listens on activation and provides `ctx.httpServer` — `register(route)` adds a named `exact`/`prefix` route (duplicate `(kind, path)` throws: route patterns are a composition-level contract, so a collision is a misconfiguration; the returned disposer removes the route), `tapIndex(transform)` adds an index.html transform applied in registration order, `port` reads the listening port (the OS-assigned value when `port` is 0), and `host` reads the configured bind host (composition-time facts other plugins adapt to, e.g. the directory-picker chooser). The match order is fixed — exact over the whole table, then longest prefix, then the static dist fallback with the locked semantics: traversal outside the dist root is 403, any miss falls back to `index.html` with HTTP 200 (SPA routing), unknown extensions ship as octet-stream, non-GET/HEAD is 405. Registration order carries no request-facing semantics.

 The package knows no harness concepts: the `/api` bridge is the connection plugin's route, plugin bundles and the HMR event stream are the modules/hmr plugins' routes. `host` accepts only `127.0.0.1` (default posture) and `0.0.0.0` (deliberate network exposure); `distIndex` is an assembly fact the composing app resolves and injects, never self-resolved (dist location is workspace knowledge of the app). Web (browser) shape only — Electron loads dist over `file://` and carries fetch over an IPC bridge, not this server. This package never prints; the URL line belongs to the shell.

--- a/packages/host/webserver/README.zh.md
+++ b/packages/host/webserver/README.zh.md
@@ -2,7 +2,7 @@

 [English](README.md) | 中文

-朴素的 HTTP 路由注册插件（默认导出 `HttpServerService`，配置为 `{host, port, distIndex}`）：一个在激活时开始监听的 `node:http` 服务器，提供 `ctx.httpServer`。`register(route)` 添加具名的 `exact`／`prefix` 路由；重复的 `(kind, path)` 会抛错，因为路由模式是组合层契约，冲突即配置错误；返回的 disposer 会移除该路由。`tapIndex(transform)` 添加按注册顺序应用的 index.html 转换，`port` 读取正在监听的端口（当 `port` 为 0 时读取 OS 分配的值）。匹配顺序固定不变：先在整张表中匹配精确路由，再匹配最长前缀，最后回退到静态 dist，并遵循固定语义：越出 dist 根目录的遍历返回 403，任何未命中项都以 HTTP 200 回退到 `index.html`（SPA 路由），未知扩展名按 octet-stream 提供，GET／HEAD 之外的方法返回 405。注册顺序不承载任何面向请求的语义。
+朴素的 HTTP 路由注册插件（默认导出 `HttpServerService`，配置为 `{host, port, distIndex}`）：一个在激活时开始监听的 `node:http` 服务器，提供 `ctx.httpServer`。`register(route)` 添加具名的 `exact`／`prefix` 路由；重复的 `(kind, path)` 会抛错，因为路由模式是组合层契约，冲突即配置错误；返回的 disposer 会移除该路由。`tapIndex(transform)` 添加按注册顺序应用的 index.html 转换，`port` 读取正在监听的端口（当 `port` 为 0 时读取 OS 分配的值），`host` 读取配置的绑定宿主（这些是其他插件据以自适应的组合期事实，例如 directory-picker 选择器）。匹配顺序固定不变：先在整张表中匹配精确路由，再匹配最长前缀，最后回退到静态 dist，并遵循固定语义：越出 dist 根目录的遍历返回 403，任何未命中项都以 HTTP 200 回退到 `index.html`（SPA 路由），未知扩展名按 octet-stream 提供，GET／HEAD 之外的方法返回 405。注册顺序不承载任何面向请求的语义。

 该包不了解任何 harness 概念：`/api` 桥接是 connection 插件的路由，插件 bundle 与 HMR（热模块替换）事件流则是 modules／hmr 插件的路由。`host` 只接受 `127.0.0.1`（默认姿态）和 `0.0.0.0`（有意向网络开放）；`distIndex` 是由组合应用解析并注入的组装事实，绝不会自行解析，因为 dist 位置属于应用的工作区知识。该服务器只服务 Web（浏览器）形态；Electron 通过 `file://` 加载 dist，并经 IPC 桥接承载 fetch，而不使用本服务器。该包从不打印内容；URL 行属于 shell。

--- a/packages/host/webserver/src/index.ts
+++ b/packages/host/webserver/src/index.ts
@@ -78,6 +78,11 @@ export class HttpServerService extends Service {
    return this.listenedPort
  }

+  /** The configured bind host (the loopback or all-interfaces literal). */
+  get host(): Config['host'] {
+    return this.config.host
+  }
+
  /**
   * Register a named route. Duplicate (kind, path) throws — route patterns are
   * a composition-level contract, so a collision is a misconfiguration.