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).

python/sdk-runtime/package.json

@@ -40,8 +40,8 @@
     "@deepseek-ai/dsh-llm-pi-ai": "workspace:^",
     "@deepseek-ai/dsh-llm-retry": "workspace:^",
     "@deepseek-ai/dsh-plan-mode": "workspace:^",
-    "@deepseek-ai/dsh-process": "workspace:^",
-    "@deepseek-ai/dsh-process-local": "workspace:^",
+    "@deepseek-ai/dsh-subprocess": "workspace:^",
+    "@deepseek-ai/dsh-subprocess-local": "workspace:^",
     "@deepseek-ai/dsh-permission": "workspace:^",
     "@deepseek-ai/dsh-paths": "workspace:^",
     "@deepseek-ai/dsh-repeat-tool-guard": "workspace:^",

python/sdk-runtime/src/deepseek_harness_runtime/runtime/cordis.yml

@@ -34,8 +34,8 @@
 
 # Local bash executor; $DSH_CWD wins over the process cwd.
 # 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'

python/sdk/tests/test_bundled_runtime.py

@@ -30,8 +30,8 @@ _CORDIS_YML = """\
     root: './sessions'
 - id: session-checkpoints
   name: '@deepseek-ai/dsh-session-checkpoint-policy'
-- id: processes
-  name: '@deepseek-ai/dsh-process-local'
+- id: subprocess
+  name: '@deepseek-ai/dsh-subprocess-local'
 - id: bash
   name: '@deepseek-ai/dsh-bash-local'
   config: