Weekly automated audit digest (post-merge oversight for the merge gate)

[sergstack]

Goal

Replace pre-merge human review of Tier 0/1 changes with a weekly automated digest — the missing post-merge oversight half of the #144 merge-gate design.

What to build

A scheduled GitHub Actions workflow (weekly cron) that:

1. Runs the full validation suite on main (all 6 scripts/check_*.py + pytest) and reports results.
2. Collects PRs merged in the last 7 days (number, title, changed-paths summary, merged-by: gate vs owner).
3. Lists open issues and PRs with no activity for 14+ days as stale candidates.
4. Opens ONE digest issue using ChatGPT/[AI OS]/Knowledge/WEEKLY_AI_OS_REVIEW_TEMPLATE.md structure, labeled ai-os, assigned to @sergstack.

The owner reads one issue per week instead of reviewing each PR.

Constraints

• Read-only against repo content: the workflow creates the digest issue and nothing else (no commits, no merges, no closing).
• Supervised-loop rules apply: no autonomous retrieval, no external services beyond GitHub API.
• Workflow lives in .github/ (Tier 2), so the implementing PR requires owner review — expected.

Acceptance

• After merge, the next scheduled run produces a digest issue with checks status, merged-PR list, and stale list; no other side effects.