refactor(runtime): collapse unused setup layers

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: 12a88a86c3cd7bcde2858bdbd874c99533100e09
-README.zh.md: f4c265a0f55c4e35e4557516593dd0da236164c5
+README.md: 08fb03d6f145c1026180d92de2421b647cb3ebbe
+README.zh.md: 592fc83223092b3406e9070e11de2b20a63232a6

packages/subprocess/subprocess/README.md

@@ -2,12 +2,12 @@
 
 English | [中文](README.zh.md)
 
-The subprocess seam (`ctx.subprocess`) is the process half of one execution world. The abstract `SubprocessService` exposes its canonical `cwd`, private `runtimeRoot`, executable lookup, ordinary managed `spawn`, and one terminal-process primitive; its vocabulary covers raw/collected stdio, process and terminal handles, exit facts, tree/session cleanup, and the managed `DSH_*` environment namespace. The local implementation lives in [`dsh-subprocess-local`](../subprocess-local/README.md).
+The subprocess seam (`ctx.subprocess`) is the process half of one execution world. The abstract `SubprocessService` exposes its canonical `cwd`, executable lookup, ordinary managed `spawn`, and one terminal-process primitive; its vocabulary covers raw/collected stdio, process and terminal handles, exit facts, tree/session cleanup, and the managed `DSH_*` environment namespace. The local implementation lives in [`dsh-subprocess-local`](../subprocess-local/README.md).
 
 ## 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.
-- `cwd` and `runtimeRoot` are absolute paths in the provider's execution world. Consumers materialize private helpers below `runtimeRoot`, never in a host-only temp directory. `resolveExecutable(command, env?, signal?)` verifies absolute commands or resolves bare names against that world's scrubbed PATH plus explicit overrides.
+- `cwd` and executable paths belong to the provider's execution world. `resolveExecutable(command, env?, signal?)` verifies absolute commands or resolves bare names against that world's scrubbed PATH plus explicit overrides.
 - 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.
 - 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).

packages/subprocess/subprocess/README.zh.md

@@ -2,12 +2,12 @@
 
 [English](README.md) | 中文
 
-子进程 seam（`ctx.subprocess`）是一个执行世界的进程部分。抽象的 `SubprocessService` 公开其规范化 `cwd`、私有 `runtimeRoot`、可执行文件查找、普通受管 `spawn` 和一项终端进程原语；其词汇涵盖原始／收集式 stdio、进程与终端句柄、退出事实、进程树／会话清理，以及受管的 `DSH_*` 环境命名空间。本地实现位于 [`dsh-subprocess-local`](../subprocess-local/README.md)。
+子进程 seam（`ctx.subprocess`）是一个执行世界的进程部分。抽象的 `SubprocessService` 公开其规范化 `cwd`、可执行文件查找、普通受管 `spawn` 和一项终端进程原语；其词汇涵盖原始／收集式 stdio、进程与终端句柄、退出事实、进程树／会话清理，以及受管的 `DSH_*` 环境命名空间。本地实现位于 [`dsh-subprocess-local`](../subprocess-local/README.md)。
 
 ## 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。
-- `cwd` 和 `runtimeRoot` 是提供方执行世界中的绝对路径。消费方在 `runtimeRoot` 之下物化私有辅助程序，绝不使用仅宿主可见的临时目录。`resolveExecutable(command, env?, signal?)` 验证绝对命令，或根据该执行世界清理后的 PATH 加显式覆盖来解析裸名称。
+- `cwd` 和可执行文件路径属于提供方的执行世界。`resolveExecutable(command, env?, signal?)` 验证绝对命令，或根据该执行世界清理后的 PATH 加显式覆盖来解析裸名称。
 - 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]`。
 - 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）。

packages/subprocess/subprocess/src/index.ts

@@ -78,8 +78,8 @@ declare module 'cordis' {
  * duplicate-service behavior).
  *
  * Implementations must honor these semantics:
- * - {@link cwd}, {@link runtimeRoot}, and executable paths belong to one
- *   execution world shared with the mounted filesystem provider.
+ * - {@link cwd} and executable paths belong to one execution world shared
+ *   with the mounted filesystem provider.
  * - {@link spawn} returns immediately with a live handle; `done` resolves at
  *   process close with exit facts and rejects only for spawn-level failures.
  * - Collect-mode readers are offset-based and non-consuming, so independent
@@ -107,9 +107,6 @@ export abstract class SubprocessService extends Service {
   /** Canonical default cwd in this provider's execution world. */
   abstract readonly cwd: string
 
-  /** Private directory for runtime artifacts in this provider's execution world. */
-  abstract readonly runtimeRoot: string
-
   /**
    * Resolve one configured executable in this provider's execution world.
    * Absolute paths are verified; bare names use the provider's scrubbed PATH

packages/subprocess/subprocess/tests/service.spec.ts

@@ -17,7 +17,6 @@ import type {
  */
 class StubSubprocessService extends SubprocessService {
   readonly cwd = '/stub'
-  readonly runtimeRoot = '/stub/.runtime'
 
   async resolveExecutable(command: string): Promise<string> {
     return `/bin/${command}`