Clarify PowerShell local demo steps

[AlexMnrs]

Summary

• Add PowerShell-ready API health checks to the local demo runbook.
• Show a copy-pasteable CPU-only job submission that captures the returned job id.
• Recommend curl.exe and --data "@file.json" to avoid PowerShell alias and JSON quoting pitfalls.

Closes #4

Validation

• Parsed the added PowerShell snippets with System.Management.Automation.Language.Parser.
• git diff --check.
• Created a temporary virtual environment, installed .[test], and ran python -m pytest tests/unit -q successfully.

Note

I did not start the Docker Compose stack locally for this docs-only change; the commands mirror the existing README endpoints and checked-in examples/job.sleep.json fixture.

[chendbox]

Thanks Alex for the PowerShell improvements here.

One fix needed: the submit response returns job_id, not id, so the status example should use $job.job_id instead of $job.id.

Suggested change:
curl.exe -sS "http://localhost:8001/v1/jobs/$($job.job_id)"

[AlexMnrs]

Thanks for catching that. I updated the runbook to use the returned job_id in the status request, and adjusted the preceding sentence to match.

[chendbox]

Thanks for the update, the PS example looks good now.