Merge commit 'a9cc0fddb40be295c43cb2badb4cbcb2b032556c' into codex/product-providers-pr2-claude-code

# Conflicts:
#	.agents/notes/proposed/feature/2026-08-04-claude-code-and-codex-subagent-backends.i18n.yaml
#	.agents/notes/proposed/feature/2026-08-04-claude-code-and-codex-subagent-backends.md
#	.agents/notes/proposed/feature/2026-08-04-claude-code-and-codex-subagent-backends.zh.md
#	docs/core-data-structures/subprocess.i18n.yaml
#	packages/subprocess/subprocess/README.i18n.yaml

packages/subprocess/subprocess/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/subprocess/subprocess/README.md
-README.md: 13c634429bfae9408dc732aea69df673e5da87aa
-README.zh.md: fe7b28d3a8f256e0eb9b4cbb98093bac33816fdf
+README.md: e59dd96df036826f36bd0286c977438d2d87d1cf
+README.zh.md: 2268af3cf2cfdac87ce9677c8d6d81c6be4c9631

packages/subprocess/subprocess/README.md

@@ -7,7 +7,7 @@ The subprocess seam (`ctx.subprocess`). The abstract `SubprocessService` exposes
 ## Contract
 
 - `spawn(spec)` returns immediately with a live handle; `done` resolves at process close with exit facts (`SubprocessOutcome` carries no output and no cause classification) and rejects only for spawn-level failures.
-- The spec is fully explicit — argv, cwd, per-stream stdio dispositions, grace — because deployment-varying defaults belong to the calling seam's config, not to a hidden subprocess-service default (the `dsh-bash` request/spec split is the owning template). `argv` is never shell-interpreted; a consumer that wants a shell passes `['bash', '-c', command]` itself.
+- The spec is fully explicit — argv, cwd, per-stream stdio dispositions, grace — because deployment-varying defaults belong to the calling seam's config, not to a hidden subprocess-service default (the `dsh-bash` request/spec split is the owning template). Grace must be positive, finite, and no greater than [`MAX_TIMER_DELAY_MS`](../../util/timeout/README.md), so the implementation can represent it with one Node timer instead of accepting a value that Node collapses to one millisecond. `argv` is never shell-interpreted; a consumer that wants a shell passes `['bash', '-c', command]` itself.
 - Stdio is Node-shaped per stream: `'pipe'` hands the caller the raw stream for its own protocol framing (LSP JSON-RPC, ACP ndjson), `'inherit'` passes the parent descriptor through for diagnostics, and collect mode (`{ maxBytes, spill? }`) buffers a bounded tail with an optional full-stream spill file. Collect readers take whole-stream byte offsets and never consume, so independent readers cannot steal one another's deltas; a read whose offset slid out of the in-memory tail is `lossy` and points at the spill file when one exists. Collected output stays readable after settlement.
 - Termination is tree-scoped on every platform (POSIX detached groups with direct-child fallback; Windows `taskkill /T`): `terminate()` — the only termination verb — escalates SIGTERM→grace→SIGKILL (idempotent, driven by the spec's abort signal too, a no-op once the tree is gone), and `waitForExit(signal?)` observes whole-tree liveness so a consumer-owned teardown ladder holds each tier on real quiescence — the manager reacts but never classifies why (callers own deadlines, teardown ladders, and cause classification).
 - `scrubbedParentEnv()` / `SENSITIVE_ENV_PATTERN` are the one shared scrub definition: ambient credential-shaped and `DSH_*` names are dropped, and the spec's explicit `env` merges after the scrub with no namespace validation — a string deliberately forwards or overrides a value, while an `undefined` tombstone removes an ordinary ambient entry. Spawners that cannot route through the service (node-pty backends, SDK-managed transports) import the scrub.

packages/subprocess/subprocess/README.zh.md

@@ -7,7 +7,7 @@
 ## 契约
 
 - `spawn(spec)` 立即返回一个活动句柄；`done` 在进程关闭时以退出事实 resolve（`SubprocessOutcome` 不携带输出，也不携带原因分类），仅在 spawn 层面失败时 reject。
-- spec 完全显式（argv、cwd、按流划分的 stdio 处置方式（disposition）、宽限期），因为随部署变化的默认值属于调用方 seam 的配置，而不属于某个隐藏的子进程默认值（`dsh-bash` 的 request/spec 拆分是这条规则的所属模板）。`argv` 绝不经过 shell 解释；需要 shell 的消费方自行传入 `['bash', '-c', command]`。
+- spec 完全显式（argv、cwd、按流划分的 stdio 处置方式（disposition）、宽限期），因为随部署变化的默认值属于调用方 seam 的配置，而不属于某个隐藏的子进程默认值（`dsh-bash` 的 request/spec 拆分是这条规则的所属模板）。宽限期须为正有限值，且不得大于 [`MAX_TIMER_DELAY_MS`](../../util/timeout/README.md)，这样实现便可用一个 Node 定时器表示它，而不会接受会被 Node 折叠为 1 毫秒的值。`argv` 绝不经过 shell 解释；需要 shell 的消费方自行传入 `['bash', '-c', command]`。
 - stdio 按流采用 Node 风格：`'pipe'` 把原始流交给调用方做自己的协议分帧（LSP 的 JSON-RPC、ACP（Agent Client Protocol）的 ndjson），`'inherit'` 直通父进程描述符以承载诊断输出，收集模式（collect）`{ maxBytes, spill? }` 则缓冲一段有界尾部，外加可选的完整流 spill 文件。收集模式的读取器接受全流字节偏移量且从不消费，因此独立的读取器不会抢走彼此的增量；偏移量滑出内存尾部窗口的读取标记为 `lossy`，并在 spill 文件存在时指向它。收集到的输出在结算后仍可读取。
 - 终止在每个平台上都以进程树为范围（POSIX 用 detached 进程组并以直接子进程回退；Windows 用 `taskkill /T`）：`terminate()`（唯一的终止动词）执行 SIGTERM→宽限期→SIGKILL 升级（幂等，也由 spec 的 abort 信号驱动，进程树消亡后为空操作）；`waitForExit(signal?)` 观察整棵进程树的存活状态，使消费方自有的拆卸阶梯能在真正完全停稳后才进入下一层。管理器只响应中止，但绝不判定原因（deadline、拆卸阶梯与原因分类归调用方所有）。
 - `scrubbedParentEnv()` / `SENSITIVE_ENV_PATTERN` 是唯一一份共享的环境清理定义：环境中形似凭据的名称与 `DSH_*` 名称都会被丢弃，spec 的显式 `env` 在清理后合并且不做命名空间校验——字符串会有意转发或覆盖某个值，而 `undefined` tombstone 则会删除普通的环境条目。无法把 spawn 路由到该服务的进程启动方（node-pty 后端、由 SDK 管理的传输层）会导入该环境清理定义。

packages/subprocess/subprocess/src/types.ts

@@ -80,10 +80,11 @@ export interface SubprocessSpawnSpec {
   /** Per-stream stdio dispositions. */
   stdio: SubprocessStdio
   /**
-   * Grace period in milliseconds for the {@link SubprocessHandle.terminate}
-   * escalation and for draining still-open collected pipes after the process
-   * exits (an inherited descriptor held by a surviving descendant cannot hold
-   * the outcome open indefinitely).
+   * Positive finite grace period in milliseconds, no greater than
+   * `MAX_TIMER_DELAY_MS`, for the {@link SubprocessHandle.terminate} escalation
+   * and for draining still-open collected pipes after the process exits (an
+   * inherited descriptor held by a surviving descendant cannot hold the
+   * outcome open indefinitely).
    */
   graceMs: number
   /**