The dispose ladder belongs to its consumer, not the subprocess seam
dispose 阶梯归其消费方所有，而非 subprocess seam
`SubprocessHandle.dispose(graces)` and `SubprocessDisposeGraces` put a full teardown *policy* — stdin-EOF wait, then SIGTERM, then SIGKILL, each tier bounded by a caller-supplied window — on a seam whose other verbs are single mechanisms. Only one consumer ever called it (the ACP subagent backend); bash rides `terminate()` and service teardown, and the LSP host runs its own protocol-first shutdown. Every future backe
English
Problem
SubprocessHandle.dispose(graces) and SubprocessDisposeGraces put a full teardown policy — stdin-EOF wait, then SIGTERM, then SIGKILL, each tier bounded by a caller-supplied window — on a seam whose other verbs are single mechanisms. Only one consumer ever called it (the ACP subagent backend); bash rides terminate() and service teardown, and the LSP host runs its own protocol-first shutdown. Every future backend nonetheless had to implement the ladder to satisfy the interface, and the implementation carried a dsh-timeout dependency solely for the ladder's tier bounds.
Decision
The ladder moves to its one consumer. dsh-subagent-acp owns disposeAcpChild(child, eofGraceMs), built entirely on the seam's public verbs: close stdin, bound a waitForExit on eofGraceMs, then call terminate(), whose SIGTERM→spec-grace→SIGKILL escalation already owns the signal timer, and await an unbounded waitForExit() for the subprocess owner's whole-tree exit proof. The seam keeps kill/terminate/waitForExit — mechanisms, not policy — and waitForExit(signal?) is exactly the quiescence probe a consumer ladder needs to hold the cooperative tier on real tree exit without deriving another timer from the termination grace. The seam's handle loses one method and one exported interface.
Alternatives considered
Keep the ladder on the handle as a convenience. Rejected: a Service Definition method every Service Provider must implement is not a convenience, it is contract surface — and this one encodes one consumer's cooperation shape (stdin-EOF-first) as if it were process vocabulary. The seam's own README already had to caveat that children quiescing on other signals need "their own tier-1", which is the admission that the ladder is policy.
Move the ladder to a shared helper package. Rejected: one consumer. A second out-of-process backend with the same stdin-EOF cooperation shape can lift disposeAcpChild to shared code when it exists; extracting now would recreate dsh-subagent-subprocess, the single-purpose library this change deleted.
Consequences
Bought: the Service Definition is one method and one type smaller; Service Providers owe four verbs and no teardown policy; the cooperative EOF window lives beside the ACP config field that tunes it, while the subprocess owner alone owns the termination window and final join. Cost: a future backend wanting EOF-first teardown writes ~20 lines against the verbs (or lifts the ACP helper); the ladder's tier tests live in the ACP suite, and the Service Definition suite pins the verbs the ladder composes (bounded waitForExit false before escalation and an unbounded whole-tree join after it) instead of the composed policy.
中文
问题
SubprocessHandle.dispose(graces) 与 SubprocessDisposeGraces 把一整套拆卸策略——等待 stdin EOF、再 SIGTERM、再 SIGKILL，每一层由调用方提供的时间窗约束——放在了一个其余动词均为单一机制的 seam 上。它始终只有一个消费方（ACP（Agent Client Protocol）subagent 后端）；bash 走 terminate() 与服务拆卸，LSP 主机运行自己的协议优先关闭流程。然而每个未来后端都必须实现该阶梯才能满足接口，实现包也仅为阶梯的层级时限背上了 dsh-timeout 依赖。
决策
阶梯移入其唯一消费方。dsh-subagent-acp 拥有 disposeAcpChild(child, eofGraceMs)，完全构建在 seam 的公开动词之上：关闭 stdin，以 eofGraceMs 约束一次 waitForExit，随后调用 terminate()（其 SIGTERM→spec 宽限期→SIGKILL 升级已拥有信号定时器），再无界等待 waitForExit()，由子进程责任方证明整棵进程树已经退出。seam 保留 kill／terminate／waitForExit——机制而非策略——而 waitForExit(signal?) 恰是消费方阶梯在协作层确认进程树真正退出所需的完全停稳探针，无需从终止宽限期再派生一个定时器。seam 的句柄少了一个方法和一个导出接口。
曾考虑的替代方案
**把阶梯作为便利方法留在句柄上。**否决：一个每个 Service Provider 都必须实现的 Service Definition 方法不是便利，而是约定的一部分——而这一个把某一消费方的协作模式（stdin EOF 打头）当作进程词汇来编码。seam 自己的 README 早已不得不加注「依赖其他信号才能完全停稳的子进程需要自己的第一阶」，这本身就是承认该阶梯是策略。
**把阶梯移到共享辅助包。**否决：只有一个消费方。当第二个具有相同 stdin EOF 协作模式的进程外后端出现时，可以再把 disposeAcpChild 提升为共享代码；现在抽取只会重造 dsh-subagent-subprocess——本次变更删掉的那个单一用途库。
后果
买到的：Service Definition 少了一个方法和一个类型；Service Provider 只欠四个动词，不欠拆卸策略；协作式 EOF 时间窗与调节它的 ACP 配置字段住在一起，而终止时间窗与最终的整树退出等待仅由子进程责任方拥有。代价：未来想要 EOF 打头拆卸的后端需针对这些动词写约 20 行（或直接搬 ACP 的辅助函数）；阶梯的层级测试位于 ACP 套件，Service Definition 套件转而钉住阶梯所组合的动词（升级前有界 waitForExit 返回假，升级后无界等待整棵进程树退出），而非组合后的策略。