refactor(subprocess): rename the process seam to subprocess and address review

Review feedback (tianyicui): 'process' is a poor service name. The family is
now packages/subprocess/ — @deepseek-ai/dsh-subprocess (ctx.subprocess,
abstract SubprocessService, Subprocess* vocabulary) and
@deepseek-ai/dsh-subprocess-local (LocalSubprocessService) — renamed
throughout code, compositions, docs (en+zh, pairs re-recorded), catalogs,
and gates. 'subprocess' is the precise term for managed OS children (the
Python-stdlib sense), avoids colliding with Node's global process object,
and reads as one system beside dsh-subagent-subprocess.

ds-review-bot findings addressed:
- kill() on a settled handle is now a no-op (no signal to a possibly-reused
  pgid, no referenced grace timer delaying exit); pinned by a spy test.
- The moved DshEnvironmentKey/DshEnvironment/CollectedOutput types get
  drift-checked type-equiv blocks on the new subprocess.md page, restoring
  their manifest registration.
- subprocess.md is registered in the core.md sub-page index (en+zh).

examples/headless-agent/composition.md

@@ -10,8 +10,8 @@ flowchart LR
   cfg["examples/headless-agent<br/>cordis.yml"]
   plugin_headless_llm_deepseek["llm-deepseek<br/>@deepseek-ai/dsh-llm-deepseek"]
   cfg --> plugin_headless_llm_deepseek
-  plugin_headless_processes["processes<br/>@deepseek-ai/dsh-process-local"]
-  cfg --> plugin_headless_processes
+  plugin_headless_subprocess["subprocess<br/>@deepseek-ai/dsh-subprocess-local"]
+  cfg --> plugin_headless_subprocess
   plugin_headless_bash["bash<br/>@deepseek-ai/dsh-bash-local"]
   cfg --> plugin_headless_bash
   plugin_headless_cli_agent["cli-agent<br/>@deepseek-ai/dsh-cli-demo"]
@@ -56,7 +56,7 @@ flowchart LR
 | Plugin id | Package / module |
 | --- | --- |
 | `llm-deepseek` | `@deepseek-ai/dsh-llm-deepseek` |
-| `processes` | `@deepseek-ai/dsh-process-local` |
+| `subprocess` | `@deepseek-ai/dsh-subprocess-local` |
 | `bash` | `@deepseek-ai/dsh-bash-local` |
 | `cli-agent` | `@deepseek-ai/dsh-cli-demo` |
 | `token-meter` | `@deepseek-ai/dsh-token-meter` |

examples/headless-agent/cordis.yml

@@ -20,8 +20,8 @@
         contextWindow: 128000
 
 # Managed child-process groups for the bash executor (spawn/kill/output plumbing).
-- id: processes
-  name: '@deepseek-ai/dsh-process-local'
+- id: subprocess
+  name: '@deepseek-ai/dsh-subprocess-local'
 
 - id: bash
   name: '@deepseek-ai/dsh-bash-local'

examples/headless-agent/semantic-checkpoint.cordis.snapshot.yml

@@ -18,8 +18,8 @@
     overrideFile: !!js process.env.DSH_SNAPSHOT_OVERRIDE
 
 # Managed child-process groups for the bash executor (spawn/kill/output plumbing).
-- id: processes
-  name: '@deepseek-ai/dsh-process-local'
+- id: subprocess
+  name: '@deepseek-ai/dsh-subprocess-local'
 
 - id: bash
   name: '@deepseek-ai/dsh-bash-local'

examples/headless-agent/tests/code-mode.e2e.ts

@@ -13,7 +13,7 @@ import AgentRegistry, { type Agent } from '@deepseek-ai/dsh-agent'
 
 import AgentLoop from '@deepseek-ai/dsh-agent-loop'
 import { LocalBashExecutor } from '@deepseek-ai/dsh-bash-local'
-import LocalProcessManager from '@deepseek-ai/dsh-process-local'
+import LocalSubprocessService from '@deepseek-ai/dsh-subprocess-local'
 import * as ToolBash from '@deepseek-ai/dsh-tool-bash'
 import * as LlmDeepSeek from '@deepseek-ai/dsh-llm-deepseek'
 import { WorkerCodeRuntime } from '@deepseek-ai/dsh-code-runtime-worker'
@@ -56,7 +56,7 @@ async function codeModeHarness(cwd: string): Promise<Context> {
   await harness.plugin(AgentRegistry)
   await harness.plugin(AgentLoop, { agents: [] })
   await harness.plugin(LlmDeepSeek)
-  await harness.plugin(LocalProcessManager)
+  await harness.plugin(LocalSubprocessService)
   await harness.plugin(LocalBashExecutor, { cwd, timeoutMs: 30_000 })
   await harness.plugin(ToolBash)
   await harness.plugin(WorkerCodeRuntime, {})
@@ -116,7 +116,7 @@ async function backgroundCodeModeHarness(cwd: string): Promise<Context> {
   const harness = await typedCodeModeHarness()
   await harness.plugin(LocalTaskService)
   await harness.plugin(ToolTasks, {})
-  await harness.plugin(LocalProcessManager)
+  await harness.plugin(LocalSubprocessService)
   await harness.plugin(LocalBashExecutor, { cwd, timeoutMs: 30_000 })
   await harness.plugin(ToolBash)
   return harness

examples/headless-agent/tests/fixtures/goal-domain/cordis.yml

@@ -3,8 +3,8 @@
   name: '../cli-mock-llm.ts'
 
 # Managed child-process groups for the bash executor (spawn/kill/output plumbing).
-- id: processes
-  name: '@deepseek-ai/dsh-process-local'
+- id: subprocess
+  name: '@deepseek-ai/dsh-subprocess-local'
 
 - id: bash
   name: '@deepseek-ai/dsh-bash-local'

examples/headless-agent/tests/fixtures/time-context.cordis.yml

@@ -3,8 +3,8 @@
   name: './time-context-mock-llm.ts'
 
 # Managed child-process groups for the bash executor (spawn/kill/output plumbing).
-- id: processes
-  name: '@deepseek-ai/dsh-process-local'
+- id: subprocess
+  name: '@deepseek-ai/dsh-subprocess-local'
 
 - id: bash
   name: '@deepseek-ai/dsh-bash-local'

examples/headless-agent/tests/harness.ts

@@ -4,7 +4,7 @@ import type { Agent } from '@deepseek-ai/dsh-agent'
 import AgentLoop from '@deepseek-ai/dsh-agent-loop'
 import { mountAgentLoopTestDependencies } from '@deepseek-ai/dsh-agent-loop-testkit'
 import { LocalBashExecutor } from '@deepseek-ai/dsh-bash-local'
-import LocalProcessManager from '@deepseek-ai/dsh-process-local'
+import LocalSubprocessService from '@deepseek-ai/dsh-subprocess-local'
 import * as ToolBash from '@deepseek-ai/dsh-tool-bash'
 import * as ToolTodo from '@deepseek-ai/dsh-tool-todo'
 import * as LlmDeepSeek from '@deepseek-ai/dsh-llm-deepseek'
@@ -60,7 +60,7 @@ export async function codingHarness(workdir: string, options: CodingHarnessOptio
   await ctx.plugin(LlmDeepSeek, options.modelContextWindow === undefined ? {} : {
     models: [{ id: 'deepseek-v4-flash', contextWindow: options.modelContextWindow }],
   })
-  await ctx.plugin(LocalProcessManager)
+  await ctx.plugin(LocalSubprocessService)
   await ctx.plugin(LocalBashExecutor, { cwd: workdir, timeoutMs: 30_000 })
   await ctx.plugin(ToolBash)
   await ctx.plugin(ToolTodo)