refactor(process): split the process manager out of the bash executor

New process/ capability family: @deepseek-ai/dsh-process owns ctx.processes —
abstract ProcessManager.spawn(spec) over a fully-explicit ProcessSpawnSpec —
plus the shared DSH_* managed-environment and CollectedOutput vocabulary;
@deepseek-ai/dsh-process-local carries the former bash-local run.ts plumbing
(detached groups, tail-keep spill-backed output, credential scrub, kill
escalation, kill-and-join disposal) with no config of its own.

dsh-bash-local becomes a consumer: it keeps command defaulting, the fused
deadline timedOut/aborted classification, the model-friendly terminal env
(now merged through the ordinary env channel), and the [stderr]-marked
background read merge, and spawns through ctx.processes. Background-process
lifetime moves to the manager, so an executor reload no longer kills live
background work; a background spawn failure is injected once into the read
path instead of being buffered as fake stderr. dsh-bash re-exports the moved
vocabulary so bash consumers keep one import root; dsh-bash-sandbox only
redeclares the inherited inject.

Every composition loading a bash executor now loads dsh-process-local (CLI,
examples, python bundled runtime, create-sdk bash feature, inline test
configs).

docs/core-data-structures/bash.zh.md

@@ -2,23 +2,13 @@
 
 [English](bash.md) | 中文
 
-bash 执行 seam 分为接口（[dsh-bash](../../packages/bash/bash)，`ctx.bash`）、实现（[dsh-bash-local](../../packages/bash/bash-local) 与 [dsh-bash-sandbox](../../packages/bash/bash-sandbox)）和消费方（[dsh-tool-bash](../../packages/bash/tool-bash)，即 `bash` schema）。通用后台任务的 id、所有权与控制位于 [tasks.md](tasks.md)；本 seam 返回一个不含任务概念的进程句柄。
+bash 执行 seam 分为接口（[dsh-bash](../../packages/bash/bash)，`ctx.bash`）、实现（[dsh-bash-local](../../packages/bash/bash-local) 与 [dsh-bash-sandbox](../../packages/bash/bash-sandbox)）和消费方（[dsh-tool-bash](../../packages/bash/tool-bash)，即 `bash` schema）。通用后台任务的 id、所有权与控制位于 [tasks.md](tasks.md)；本 seam 返回一个不含任务概念的进程句柄。原始进程组机制位于[进程管理器 seam](process.md)之后。
 
 源码：[`packages/bash/bash/src/types.ts`](../../packages/bash/bash/src/types.ts)
 
 ## 受管 shell 环境命名空间
 
-`DSH_*` 变量是归 Harness 所有的子进程事实。面向模型的 bash 工具通过 `ctx.bashEnv` 收集它们，再经由 `BashExecRequest.dshEnv` 传递；执行器在合并当前快照之前会移除继承而来的 `DSH_*` 名称。
-
-```ts type-equiv
-/** One environment key inside the managed {@link DSH_ENV_PREFIX} namespace. */
-type DshEnvironmentKey = `${typeof DSH_ENV_PREFIX}${string}`
-```
-
-```ts type-equiv
-/** Trusted DeepSeek Harness variables for one bash execution. */
-type DshEnvironment = Readonly<Record<DshEnvironmentKey, string>>
-```
+`DSH_*` 变量是归 Harness 所有的子进程事实。面向模型的 bash 工具通过 `ctx.bashEnv` 收集它们，再经由 `BashExecRequest.dshEnv` 传递；进程管理器在合并当前快照之前会移除继承而来的 `DSH_*` 名称。`DshEnvironmentKey`／`DshEnvironment` 词汇归[进程管理器 seam](process.md)所有，由 `dsh-bash` 重导出。
 
 ## 请求与规格：`resolve()` 拆分
 
@@ -145,19 +135,7 @@ interface BashRunResult {
 }
 ```
 
-每个流是一个 `CollectedOutput`：（可能被截断的）文本加恢复信息。截断时，`text` 是**尾部**，完整流溢出到一个私有文件：
-
-```ts type-equiv
-/** One captured stream: the (possibly truncated) text plus recovery info. */
-interface CollectedOutput {
-  /** Collected text — the TAIL of the stream when truncated. */
-  text: string
-  /** True when bytes were dropped from `text`. */
-  truncated: boolean
-  /** Path to a file holding the COMPLETE stream, when truncated and available. */
-  spillPath?: string
-}
-```
+每个流是一个 `CollectedOutput`：（可能被截断的）文本加恢复信息；截断时，`text` 是**尾部**，完整流溢出到一个私有文件。该形状归[进程管理器 seam](process.md)所有，由 `dsh-bash` 重导出。
 
 ## 文件沙箱：`BashSandboxInfo`