Add Screenshots for Quickstart and Lease Recovery Demo

[chendbox]

Summary

Add a small set of screenshots or annotated images for the quickstart and lease recovery demo flow.

Why This Matters

MLIS is partly a runnable learning artifact. Screenshots help new visitors understand the operator console, job lifecycle, and recovery workflow more quickly.

Scope

Suggested additions:

• operator console overview
• job detail view for a running job
• lease recovery before/after worker reassignment
• optional annotated image for the quickstart path

Acceptance Criteria

• add 2 to 4 useful screenshots under docs/images/
• reference them from README.md or a runbook
• images should support the public demo story, not just decorate the page

Good Starting Points

• README.md
• docs/runbooks/local-demo.md
• docs/images/