[WeiLinCool]

Closes #413

What was wrong

With dsh-ops-hide-official enabled (replaceTools non-empty) on DSH 0.2.1, every scoped prompt assembly is rejected:

READINESS_BLOCKED (EXECUTOR_UNAVAILABLE): dsh-ops hide-official cannot verify selected
replacements: assembled tool schemas unavailable. ...

The guard read the waterfall payload's tool array unconditionally:

if (!Array.isArray(result?.tools)) throw block(context.scope, 'assembled tool schemas unavailable')
const leaked = result.tools.map(schema => schema.name).filter(hideable)

DSH 0.2.1 (9d0c97b9d2 feat(tools): admit conditional tools per step) transforms a PromptPresentation and attaches tools only after the waterfall returns, so result.tools is always undefined there and the guard can never pass. #387 / 211dc3e fixed the same contract change on the PTC side (hasPtcInstruction, text-only hooks); this is the remaining occurrence.

Minimal reproduction, used as the regression test — a listener that reproduces the host's shape (drop tools before next(), re-attach after, exactly like the host's return { ...transformed, tools }):

ctx.on('system-prompt/assemble', async (assembly, _context, next) => {
  const tools = assembly.tools
  delete assembly.tools
  return { ...await next(), tools }
})

On main@dfafddc that assembly rejects with assembled tool schemas unavailable; with this change it resolves and the selected official tools stay hidden.

The change

• src/official-tool-hiding.ts: when the payload carries no tool array, resolve the selected official names through the scope view (tools.get(tool, context.scope)) instead of failing on the missing array. A host that still supplies schemas keeps the existing assembled-surface assertion, unchanged.
• The fallback stays fail-closed: a selected official tool that is still resolvable in the scope is still reported as a leak, with the same message as before.
• test/lib/official-tool-hiding.mjs: regression that mounts the replacement surface, reproduces the 0.2.1 payload shape, and asserts the assembly succeeds and the visible surface is intact.
• docs/CHANGELOG.md: ## [Unreleased] entry, English and Chinese.

Deliberately not changed: the collapsed/entry.error interaction above the guard (a collapsed PTC scope still needs an assembled array to be proven), and the PTC-side predicate, which 211dc3e already handles.

Validation

$ npx tsc -p . --noEmit
(no output)

$ node scripts/build.mjs
build: generated PTC declarations for 18 capabilities (113501 bytes)
build: compiled src/ to lib/ and copied 35 assets

$ node test/run.mjs official-tool-hiding
  ok   a host that appends tools after assembly still verifies the visible surface
dsh-ops official-tool-hiding: all 30 checks passed
dsh-ops test: 1 suite(s) passed in 2s

$ npm run check:size
check-file-size: 426 code file(s) checked, all at or under 1000 lines (longest: bench/setup/profile.mjs (927))

$ node scripts/validate-manifest.mjs
validate-manifest: all 133 checks passed

Red without the change, on the same base commit dfafddc with only the new test applied:

  FAIL a host that appends tools after assembly still verifies the visible surface
       Error: READINESS_BLOCKED (EXECUTOR_UNAVAILABLE): dsh-ops hide-official cannot verify
       selected replacements: assembled tool schemas unavailable. ...

Also checked end-to-end against a real DSH 0.2.1-rc.3 AgentLoop with a scripted provider: before, the session's second assembly fails the same way; after, the turn completes. That run is not part of the suite (it needs a 0.2.1 host), so it is evidence only.

$ gh run view 40269009751 --json url,event,conclusion --jq '"\(.url) \(.event) \(.conclusion)"'
https://github.com/T-Auto/dsh-ops/actions/runs/40269009751 pull_request success

• 本 PR 有一次 pull_request 事件触发的 CI required run（上方 URL）
• npm run verify 相关读数已贴出（本机缺少可用的嵌套 sandbox，PTC 程序执行类用例在本机跳过，故只贴本次涉及套件与门禁脚本的实际输出）
• 撤掉本次实现后新用例变红（红/绿两端都有记录）
• docs/CHANGELOG.md 的 ## [Unreleased] 已加中英条目
• 未新增依赖，未改 package.json

Environment

• macOS arm64 (darwin 25), Node 24.17.0
• Base: upstream main at dfafddc
• Install channel: source checkout, npm ci --ignore-scripts + npm run build