Integrate CLI Codex outputs into Automated Status Summary

[stranske]

Why

Context / problem:

• The Automated Status Summary in PR bodies currently only shows workflow run results
• When the CLI-based Codex (via reusable-codex-run.yml) completes iterations, there's no visibility into:
  • What tasks Codex completed in each round
  • The final message/output from Codex
  • How many files were changed
  • Whether commits were pushed successfully
• This makes it hard to track CLI Codex progress vs the UI version
• The keepalive loop evaluation outputs (iteration count, tasks remaining, etc.) are logged but not surfaced to the PR summary

Goal:

• Capture CLI Codex outputs and integrate them into the Automated Status Summary
• Provide visibility into Codex iteration progress and outcomes
• Show what changed in each round

Tasks

• Update reusable-codex-run.yml to emit structured outputs:
  • Add output for final-message from Codex action
  • Add output for files-changed (count of modified files)
  • Add output for commits-pushed (boolean)
  • Write iteration summary to GITHUB_STEP_SUMMARY
• Create new section in PR body for CLI Codex status:
  • Add <!-- codex-cli-status:start --> / <!-- codex-cli-status:end --> markers
  • Show last iteration number and outcome
  • Show tasks completed this round
  • Show link to workflow run logs
• Update agents_pr_meta_update_body.js to populate the new section:
  • Fetch latest keepalive loop run results
  • Extract Codex outputs from workflow artifacts or step summaries
  • Format and insert into PR body
• Update keepalive_loop.js to pass iteration context to the summary:
  • Include current iteration number in output
  • Include tasks remaining count
  • Include estimated rounds to completion
• Add tests for the new integration:
  • Test output extraction from workflow runs
  • Test PR body section formatting
  • Test edge cases (no Codex runs, failed runs, etc.)

Acceptance criteria

• CLI Codex iterations are visible in the PR body Automated Status Summary
• Each iteration shows: round number, tasks attempted, outcome, and link to logs
• The summary updates automatically after each keepalive loop run
• Existing UI Codex tracking (if any) continues to work