refactor(subprocess): keep terminate() as the seam's only termination verb

Delete kill(signal?) from SubprocessHandle: consumers stop a process only
through terminate()'s tree-scoped SIGTERM→graceMs→SIGKILL escalation
(idempotent, also driven by the spec's abort signal, a no-op once the tree
is gone). The single-signal verb had exactly one consumer family —
lsp-local — and what it bought there was a private re-implementation of
the same escalation. The internal kill closure stays in spawn.ts as the
dispose ladder's tier primitive; terminate() now routes through it too.

lsp-local collapses onto the seam's escalation:
- LspConnection replaces its terminate()/kill() pair with one terminate()
  that delegates to handle.terminate(). Behavior change: the
  framing-failure path terminates instead of instant SIGKILL, so a
  misbehaving server now gets SIGTERM plus the killGraceMs window to
  flush before SIGKILL.
- ConnectionSpec.pipeDrainGraceMs becomes killGraceMs: one grace, the
  spawn spec's graceMs, drives both the escalation window and post-exit
  pipe draining (the provider already passed killGraceMs for it).
- LspInstance.forceTerminate() drops its hand-rolled bounded first wait
  (LSP_KILL_GRACE) and escalateProcessTree (deleted with its export and
  unit test): the seam's escalation already commits to SIGKILL after
  killGraceMs, so only the unbounded quiescence awaits stay load-bearing.

Tests: kill()-shaped spawn specs become terminate()-shaped or fold into
the terminate() suites (group-wide delivery; the settled no-op case was
already pinned by 'terminate() after the tree died'); tree-survivor
coverage is intact. A stderr-'inherit' disposition test completes the
stdout/stderr symmetry so the scoped subprocess+lsp coverage gate stands
alone instead of leaning on subagent-acp's cross-package runs.

Docs: SubprocessHandle type-equiv block, seam/impl/group READMEs, and the
consumer-migration Agent Note lose the kill(signal?) vocabulary (zh pairs
re-recorded); cordis api/services catalogs regenerated.

.agents/notes/implemented/architecture/2026-07-26-subprocess-consumer-migration.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
-2026-07-26-subprocess-consumer-migration.md: 805f27ba2e72a7f29d1b32053add95b8c33a62e2
-2026-07-26-subprocess-consumer-migration.zh.md: 41bdf04bc03517cf9fe10a61a565e442ecee5520
+2026-07-26-subprocess-consumer-migration.md: 9353e515e4d700e59bc771b5e38648594e58466e
+2026-07-26-subprocess-consumer-migration.zh.md: fa7d8dfdbda6ddbf30e4799d130a71e1a476ab42

.agents/notes/implemented/architecture/2026-07-26-subprocess-consumer-migration.md

@@ -14,7 +14,7 @@ The seam's vocabulary is now Node-shaped, and every spawner that can ride the se
 
 - **Per-stream stdio dispositions** on `SubprocessSpawnSpec`: `'pipe'` (the raw `Readable`/`Writable`, for consumer-owned protocol framing), `'inherit'` (diagnostics to the parent's stream), and collect mode `{ maxBytes, spill? }` — the original bounded tail-keep shape, with the spill file now optional so a diagnostic tail (a language server's stderr) buffers without touching disk. stdin is `'ignore'`, `'pipe'`, or `{ data }` (write-and-close batch).
 - **`SubprocessOutcome` carries exit facts only** (Node's close-event vocabulary); collected output stays readable through `handle.collected` after settlement (spill fds seal at the settle boundary), so batch and streaming callers share one access path and nothing is copied into the outcome.
-- **Tree-scoped termination, split Node-style**: `kill(signal?)` sends one signal and is a no-op after settlement; `terminate()` owns the SIGTERM→grace→SIGKILL escalation (and serves the spec's abort signal); `waitForExit()` polls tree liveness (POSIX group probe; direct-child boundary on Windows); `dispose(graces)` is the cooperative stdin-EOF→SIGTERM→SIGKILL ladder absorbed from `subagent-subprocess`, memoized per handle. Windows tree termination (`taskkill /T`, injectable) moved in from lsp-local, so tree semantics are platform-correct for every consumer.
+- **Tree-scoped termination behind one verb**: `terminate()` owns the SIGTERM→grace→SIGKILL escalation (serves the spec's abort signal too, and is a no-op once the tree is gone) — the handle exposes no single-signal `kill(signal?)`, so a consumer cannot skip the grace window; `waitForExit()` polls tree liveness (POSIX group probe; direct-child boundary on Windows); `dispose(graces)` is the cooperative stdin-EOF→SIGTERM→SIGKILL ladder absorbed from `subagent-subprocess`, memoized per handle. Windows tree termination (`taskkill /T`, injectable) moved in from lsp-local, so tree semantics are platform-correct for every consumer.
 - **One scrub definition**: `scrubbedParentEnv()`/`SENSITIVE_ENV_PATTERN` live on the seam. Spawners that cannot route the spawn itself through the service — pty-local (node-pty owns the fork) and mcp-client (the MCP SDK owns the transport spawn) — import the function, so environment policy is single-sourced even where process ownership is not; the SDK helper's `scrubEnvironment()` defaults through it as well.
 
 Migrations landed with the reshape: **bash-local/bash-sandbox** (collect modes + batch stdin; the bash `kill()` maps to `terminate()` so `task_kill` keeps escalation semantics), **lsp-local** (piped protocol streams + a no-spill collected stderr tail; `LspConnection` takes the seam's spawn function; its private tree-op helpers deleted), **subagent-acp** (piped ndjson streams + inherited stderr; spawn failure surfaces through `done` rejection into the same startup race; disposal is `handle.dispose` with the plugin's configured graces). **`dsh-subagent-subprocess` is deleted** — the dispose ladder and scrub are the seam's; the unused isolated-config-dir helper died with it (no consumer existed).
@@ -35,4 +35,4 @@ Compositions mounting lsp-local or subagent-acp now load `dsh-subprocess-local`
 
 Bought: one implementation of tree signalling, escalation, the dispose ladder, bounded collection, and the scrub, tested once in `dsh-subprocess-local`'s suites (including injected-platform Windows coverage that lsp-local's private copy never had); lsp-local and subagent-acp shed their process plumbing and their children now survive plugin reloads and die with composition teardown like bash's; a whole package (`dsh-subagent-subprocess`) is gone. The seam README's "one consumer family" limitation is retired.
 
-Cost: the seam is wider — three stdio modes and four termination verbs instead of one of each — so a future backend implements more surface; the compositions for lsp-local/subagent-acp each carry the subprocess row now; and `SubprocessOutcome` no longer carries output, a breaking shape change inside the still-unreleased stack (the PR2 layer was updated in place rather than shimmed, per the pre-release stance). pty-local/mcp-client/SDK/test-support spawns remain outside the service by ownership, with the scrub as the shared floor.
+Cost: the seam is wider — three stdio modes and the terminate/waitForExit/dispose lifecycle surface instead of one mode and one verb — so a future backend implements more surface; the compositions for lsp-local/subagent-acp each carry the subprocess row now; and `SubprocessOutcome` no longer carries output, a breaking shape change inside the still-unreleased stack (the PR2 layer was updated in place rather than shimmed, per the pre-release stance). pty-local/mcp-client/SDK/test-support spawns remain outside the service by ownership, with the scrub as the shared floor.

.agents/notes/implemented/architecture/2026-07-26-subprocess-consumer-migration.zh.md

@@ -14,7 +14,7 @@ Status: implemented
 
 - **按流划分的 stdio 处置方式（disposition）**，位于 `SubprocessSpawnSpec` 上：`'pipe'`（原始的 `Readable`/`Writable`，供消费方自有的协议分帧使用）、`'inherit'`（诊断输出直通父进程的流），以及收集模式（collect）`{ maxBytes, spill? }`——即最初的有界尾部保留形状，只是 spill 文件改为可选，使诊断尾部（例如语言服务器的 stderr）无需落盘即可缓冲。stdin 则为 `'ignore'`、`'pipe'` 或 `{ data }`（写完即关闭的批量形式）。
 - **`SubprocessOutcome` 只承载退出事实**（Node close 事件的词汇）；收集到的输出在结算后仍可经 `handle.collected` 读取（spill 文件描述符在结算边界封存），因此批量与流式调用方共用一条访问路径，也没有任何内容被复制进这份结果。
-- **以进程树为范围的终止，按 Node 风格拆分**：`kill(signal?)` 只发送一个信号，结算后为空操作；`terminate()` 拥有 SIGTERM→宽限期→SIGKILL 升级（并承接 spec 的 abort 信号）；`waitForExit()` 轮询进程树存活状态（POSIX 进程组探测；Windows 上以直接子进程为界）；`dispose(graces)` 是从 `subagent-subprocess` 吸收来的协作式 stdin EOF→SIGTERM→SIGKILL 阶梯，按句柄 memoize 化。Windows 进程树终止（`taskkill /T`，可注入）自 lsp-local 迁入，因此每个消费方拿到的进程树语义在各平台上都正确。
+- **以进程树为范围的终止，集中在一个动词后面**：`terminate()` 拥有 SIGTERM→宽限期→SIGKILL 升级（也承接 spec 的 abort 信号，进程树消亡后为空操作）——句柄不暴露单信号的 `kill(signal?)`，因此消费方无法跳过宽限窗口；`waitForExit()` 轮询进程树存活状态（POSIX 进程组探测；Windows 上以直接子进程为界）；`dispose(graces)` 是从 `subagent-subprocess` 吸收来的协作式 stdin EOF→SIGTERM→SIGKILL 阶梯，按句柄 memoize 化。Windows 进程树终止（`taskkill /T`，可注入）自 lsp-local 迁入，因此每个消费方拿到的进程树语义在各平台上都正确。
 - **凭据清除只有一份定义**：`scrubbedParentEnv()`/`SENSITIVE_ENV_PATTERN` 定义在 seam 上。无法把 spawn 本身路由到该服务的调用点——pty-local（node-pty 拥有 fork）与 mcp-client（MCP SDK 拥有传输层的 spawn）——改为导入该函数，因此即便进程所有权无法统一，环境策略仍是单一来源；SDK helper 的 `scrubEnvironment()` 默认同样委托给它。
 
 各项迁移随这次重塑一并落地：**bash-local/bash-sandbox**（收集模式 + 批量 stdin；bash 的 `kill()` 映射到 `terminate()`，因此 `task_kill` 保有升级语义），**lsp-local**（管道化的协议流 + 无 spill 的 stderr 收集尾部；`LspConnection` 改为接收 seam 的 spawn 函数；其私有的进程树操作辅助函数已删除），**subagent-acp**（管道化的 ndjson 流 + inherit 的 stderr；spawn 失败经 `done` 的 reject 汇入同一个启动竞态；dispose 就是携带插件所配置宽限期的 `handle.dispose` 调用）。**`dsh-subagent-subprocess` 已删除**——dispose 阶梯与凭据清除归 seam 所有；无人使用的隔离配置目录辅助函数随之消亡（其消费方本就不存在）。
@@ -35,4 +35,4 @@ Status: implemented
 
 换来的是：进程树信号发送、升级、dispose 阶梯、有界收集与凭据清除各自只剩一份实现，且只在 `dsh-subprocess-local` 的测试套件中测试一次（其中包括 lsp-local 的私有副本从未有过的、以注入平台方式实现的 Windows 覆盖）；lsp-local 与 subagent-acp 卸下了自己的进程管道，其子进程如今像 bash 的一样，在插件重载后存活、随组合拆除而终止；一个完整的包（`dsh-subagent-subprocess`）就此消失。seam README 中「只有一个消费方家族」的限制说明也随之退役。
 
-代价是：这道 seam 变宽了（stdio 模式从一种变为三种、终止动词从一个变为四个），未来的后端因此要实现更宽的表面；lsp-local/subagent-acp 的各组合如今都多出 subprocess 这一行组合配置；`SubprocessOutcome` 也不再承载输出，这是仍未发布的堆叠变更内部的一次破坏性形状变更（依照预发布立场，PR2 那一层被就地更新，而非加 shim）。pty-local/mcp-client/SDK/test-support 的 spawn 因所有权归属留在该服务之外，以凭据清除作为共享底线。
+代价是：这道 seam 变宽了（stdio 模式从一种变为三种、终止动词换成 terminate/waitForExit/dispose 这组生命周期表面），未来的后端因此要实现更宽的表面；lsp-local/subagent-acp 的各组合如今都多出 subprocess 这一行组合配置；`SubprocessOutcome` 也不再承载输出，这是仍未发布的堆叠变更内部的一次破坏性形状变更（依照预发布立场，PR2 那一层被就地更新，而非加 shim）。pty-local/mcp-client/SDK/test-support 的 spawn 因所有权归属留在该服务之外，以凭据清除作为共享底线。