Pilot weekly org review cadence and prompt tuning

[ss-o]

Summary

Run the new weekly org-review workflow on a real cadence and tune the prompt/output shape based on maintainer usefulness.

Scope

• run the workflow from runbooks/org-review.md on a weekly cadence for a few iterations
• note which sections create signal versus noise
• adjust the prompt template and output shape if needed
• decide whether the review should live only as a manual maintainer workflow or gain lightweight scheduling support later

Notes

A first dry-run summary has already been recorded on z-shell/.github#410.