fix(process): close review gaps from Codex round 1

- Mount LocalProcessManager in the sandbox e2e compositions (bwrap/landlock/
  seatbelt + the spine multi-project e2e) and add the spine demo's
  dsh-process-local devDependency, so SandboxBashExecutor's new inject
  resolves when those suites are enabled.
- Extend the Windows test/coverage skip to packages/process/* — the POSIX
  process-group suite moved there from packages/bash.
- Update the stale disposal contract: the bash seam JSDoc, BashProcess JSDoc,
  and core bash doc (en+zh) now state that composition teardown (the process
  manager's disposal) owns kill-and-await, and an executor-only reload leaves
  background processes running.
- Record ctx.processes in the architecture capability table and extension map
  (en+zh) and the root AGENTS.md layout tree; reword the timeout-library note
  so it describes where the plumbing and classification live today.

AGENTS.md

@@ -15,6 +15,7 @@ packages/    @deepseek-ai/dsh-<pkg> workspaces at packages/<group>/<pkg>/
   prompt/      workspace instructions
   llm/         LLM seam + the DeepSeek adapters (hand-rolled + pi-ai design twin)
   bash/        bash executor seam + local impl + model-facing bash tools
+  process/     child-process manager seam + local process-group impl
   pty/         persistent PTY seam/backend/tools
   fs/          filesystem seam + local impl + policy gate + read/write/edit tools
   lsp/         language-server seam + local stdio provider + model-facing lsp tool