fix(ci): repair monthly PR digest — gh pr list over gh search prs

[damianrosellen1]

Problem

The monthly Slack digest posted "No PRs opened or closed in this period." for every repo (VaultLens, mammalsandcomputers, farbstudio.de, bef-website-2026, next-sanity-starter) for June 2026 — despite dozens of real PRs.

Root cause: gh search prs runs over the issue-search API and does not expose mergedAt, additions, deletions, changedFiles, commits. It errors with Unknown JSON field: "mergedAt", and 2>/dev/null || echo '[]' swallowed that failure into [] → pr_count=0 → skip=true → the empty digest. Because the error is static (not repo-dependent), every repo reported zero.

Fix

1. Query via gh pr list --search (GraphQL PR API), which supports the rich fields. Drop the 2>/dev/null || echo '[]' fallback so a genuinely failed query fails the job loudly instead of faking an empty month.
2. Co-author tool attribution (Cursor/Claude/Copilot) now works:
   • the commits connection blows the GraphQL node limit in a bulk pr-list call → fetch commits per PR (cheap for a monthly job, failure-tolerant);
   • match Co-authored-by case-insensitively — Cursor writes Co-authored-by:, Claude writes Co-Authored-By:, so every Claude co-author was silently dropped before (on top of the .message field not existing — it's .messageBody).

One reusable workflow → fixes all caller repos at once.

Verification

Ran the full corrected Collect step against backendforth/next-sanity-starter for June 2026:

• 59 PRs · 41 merged · +22,011 / −11,966 lines
• author kind: 25 Dependabot / 34 Human
• tools: Claude 27 · Cursor 25

digest-context.json is valid; workflow YAML validates.

After merge

Re-post June's digest immediately via each caller's workflow_dispatch (today is July 1 → "last month" still resolves to June).

🤖 Generated with Claude Code