Merge remote-tracking branch 'origin/worktree-process-service-seam' into subprocess-simpl/d-one-env-channel

# Conflicts:
#	docs/cordis-catalog/services.md
#	docs/core-data-structures/subprocess.i18n.yaml
#	packages/lsp/lsp-local/src/connection.ts
#	packages/subagent/subagent-acp/README.i18n.yaml
#	packages/subprocess/subprocess-local/README.i18n.yaml
#	packages/subprocess/subprocess-local/src/spawn.ts
#	packages/subprocess/subprocess/README.i18n.yaml
#	packages/subprocess/subprocess/README.md
#	packages/subprocess/subprocess/README.zh.md
#	packages/subprocess/subprocess/tests/service.spec.ts

packages/subprocess/subprocess-local/README.md

@@ -6,7 +6,7 @@ Local implementation of the [`@deepseek-ai/dsh-subprocess`](../subprocess/README
 
 ## Behavior (and where it came from)
 
-- **Detached process trees with platform-correct signalling** — POSIX children are spawned `detached` (own process group) and signalled by negative pgid with a direct-child fallback; Windows terminates the tree via `taskkill /PID <pid> /T /F` (injectable for tests). `terminate()` sends SIGTERM then SIGKILL after the spec's grace (OpenCode's escalation; pipelines and subshells die with the parent); `kill(signal)` sends exactly one signal and is a no-op after settlement; `dispose(graces)` runs stdin-EOF → SIGTERM → SIGKILL with caller-supplied windows and one memoized disposal per handle. After the leader exits, still-open pipes receive the same bounded drain grace so a surviving descendant cannot hold the outcome open indefinitely. ESRCH is tolerated; daemons that re-parent away from the group can still survive — the same caveat as the surveyed tools.
+- **Detached process trees with platform-correct signalling** — POSIX children are spawned `detached` (own process group) and signalled by negative pgid with a direct-child fallback; Windows terminates the tree via `taskkill /PID <pid> /T /F` (injectable for tests). `terminate()` — the handle's only termination verb — sends SIGTERM then SIGKILL after the spec's grace (OpenCode's escalation; pipelines and subshells die with the parent) and is a no-op once the tree is gone; `waitForExit()` polls whole-tree liveness so consumer teardown confirms real quiescence. After the leader exits, still-open pipes receive the same bounded drain grace so a surviving descendant cannot hold the outcome open indefinitely. ESRCH is tolerated; daemons that re-parent away from the group can still survive — the same caveat as the surveyed tools.
 - **Per-stream dispositions** — `'pipe'` hands the raw stream to the caller untouched (protocol framing stays consumer-owned); `'inherit'` passes the parent descriptor through; collect mode keeps the in-memory TAIL beyond its cap (errors and results cluster at the end — pi/OpenCode rationale) while the FULL stream is appended to a private temp file when a spill cap is configured — omitting `spill` keeps only the tail, the diagnostic shape. A stream larger than the spill cap discards its now-incomplete spill and returns only the marked truncated tail; spill fds are sealed at settlement, and a failed final close withholds the path rather than advertising an incomplete file. Spill files are `0600` with random names under a lazily-created `0700` per-process directory.
 - **Credential scrub + explicit merge** — `process.env` minus credential-shaped vars (`*KEY*`/`*SECRET*`/`*TOKEN*`) and all ambient `DSH_*` names; the spec's explicit `env` merges after that scrub with no namespace validation, so a deliberately supplied credential or current `DSH_*` fact wins while stale nested-harness identity cannot leak in ambiently. Supplied stdin is written and closed; otherwise fd 0 is `/dev/null`. See the [stdin/env Agent Note](../../../.agents/notes/implemented/architecture/2026-06-30-bash-stdin-env-trusted-plugin-surface.md) and [managed environment Agent Note](../../../.agents/notes/implemented/feature/2026-07-10-agent-session-identity-and-log-location.md).
 - **Offset-based reads** — collect-mode readers return deltas in whole-stream byte coordinates; the service never holds a cursor, so consumer-owned cursors (the bash background read path) and full-stream re-reads coexist, before and after settlement.