fix(phai): clean up sandbox docker containers after each eval case

[skoob13]

Problem

Docker container cleanup didn't work for long-running parallel tests.

Changes

• Added _cleanup_case_containers(task_id) in ee/hogai/eval/sandboxed/runner.py that runs docker ps -a --filter name=task-sandbox-{task_id}- --format {{.ID}} and force-removes each match.
• Wrapped the body of run_eval_case in a try / finally so the cleanup fires on both the success and exception branches, regardless of what the workflow's own cleanup does.
• Offloaded the cleanup to a worker thread via asyncio.to_thread so docker rm -f doesn't block the event loop while Docker waits on container shutdown.

Scoping by task_id prefix (get_sandbox_name_for_task in products/tasks/backend/temporal/process_task/utils.py:597) guarantees we never touch a concurrently-running case's container.

How did you test this code?

• ruff check and ruff format --check pass on the modified file.
• Manual verification deferred to the next eval run: hogli test ee/hogai/eval/sandboxed/..., then watch docker ps --filter name=task-sandbox- between cases — only the in-flight case's container should appear.

Publish to changelog?

no

[github-actions]

🎭 Playwright didn't run on this PR — your changes touch code that could affect E2E behavior, but Playwright is opt-in via label now to keep CI cost down.

Add the run-playwright label if you want an E2E sweep before merging — CI will pick it up automatically.

Most PRs don't need this. Real regressions still get caught on master and fix-forward.

[greptile-apps]

Prompt To Fix All With AI

Fix the following 1 code review issue. Work through them one at a time, proposing concise fixes.

---

### Issue 1 of 1
ee/hogai/eval/sandboxed/runner.py:45-49
If `docker ps` exits with a non-zero return code without raising a Python exception (e.g. Docker daemon returns an error), `result.returncode` is never inspected, so the failure goes completely unlogged and the loop silently skips cleanup. Adding a check here surfaces this silent failure mode.

```suggestion
    except Exception:
        logger.warning("Failed to list sandbox containers for task %s", task_id, exc_info=True)
        return

    if result.returncode != 0:
        logger.warning(
            "docker ps returned exit code %d for task %s: %s",
            result.returncode,
            task_id,
            result.stderr.strip(),
        )
        return

    for container_id in result.stdout.strip().splitlines():
```

_{Reviews (1): Last reviewed commit: "fix(phai): clean up sandbox docker conta..." | Re-trigger Greptile}

[deployment-status-posthog]

Deploy status

Environment	Status	Deployed At	Workflow
dev	✅ Deployed	2026-05-28 17:12 UTC	Run
prod-us	✅ Deployed	2026-05-28 17:34 UTC	Run
prod-eu	✅ Deployed	2026-05-28 17:37 UTC	Run