Merge Gate v1 is unsatisfiable and is enforced by a document, not a system

[groupthinking]

Problem

Merge Gate v1 lives only as a Notion page. None of its eleven implementation tasks shipped:

Task	Status
MG-1 commit MERGE_POLICY.md	❌ no such file in the repo
MG-2 branch protection, 6 required checks	❌ PRs merge with red checks (#1368)
MG-3 merge queue	❌ zero merge_group triggers in .github/workflows/
MG-4 … MG-11	❌ no gate workflow, classifier, or authorization records

What actually enforced it was an agent reading the Notion page and returning PRs to draft. The daily control logs record this directly: "Six newly ready PRs were returned to draft."

Measured impact

• 61 open PRs, 59 draft, at a median 44 commits behind main
• Meanwhile 44 other PRs merged in four days — with red checks
• Stranded work got re-cut rather than landed: fix: harden API-cost webhook outbox retries (MYX-79) #869 / [WIP] Add durable API-cost outbox and canonical usage tracking #1376 are the same change 17 days apart; fix(ci): drop stale eventrelay-ci-investigator governance checks #1317, fix(ci): finish removal of eventrelay-ci-investigator workflow #1320 and fix(ci): remove orphaned ci-investigator governance test unblocking main #1342 were three PRs for one cleanup, only the third merged

Root causes

1. Evidence reset on every push. Gate 2 ("any new commit resets all gates") plus gate 7 (zero commits behind) against a main moving ~5.5 commits/day. Rebasing to satisfy freshness discards the review approval and preview just earned; re-earning them takes longer than main stays still. Only a PR born and merged inside one quiet window could pass.

2. Gates with no satisfying action.

• Gate 4 wanted a Vercel preview READY on the exact SHA — previews are routinely canceled (fix: give RedisCacheLayer an event-loop ownership contract #1368 merged with a canceled one).
• Gate 3 wanted independent review approval — CodeRabbit skips any PR lacking one of 26 labels, so an unlabeled PR could never obtain it.
• agent-completion/truth-gate failed invalid_payload on every PR without a dispatch contract, including merged ones. Fixed in fix(ci): unblock the merge gate, consolidate its competing fixes, and audit 337 branches #1377 / agent-completion/truth-gate is unsatisfiable for PRs with no linked dispatch contract #1384.

3. Mutual quarantine. Gate 6 quarantined both PRs on surface overlap, so every duplicate pair blocked itself permanently — and duplicates were what the draft backlog kept producing.

4. Unclassifiable → Class C. Everything unfamiliar silently became a human bottleneck, which is the backlog the policy existed to remove.

Fix

Replace with a policy where every gate names an action the author can take, and evidence is invalidated only by a change to what it attests to. See the PR.

The key addition: any required check failing on >50% of PRs over 7 days is automatically demoted to advisory, with an issue opened against its owner. agent-completion/truth-gate was red on ~100% of PRs for weeks and nobody noticed, because everyone had learned to ignore it.

Acceptance criteria

• MERGE_POLICY.md v2 committed with policy_version: v2 frontmatter
• Every gate states a satisfying action
• Review evidence survives a rebase that does not change the PR's own diff
• Preview gating scoped to apps/web/**
• Overlapping PRs are labeled and assigned with a deadline, never both blocked
• No zero-commits-behind requirement
• The 50% failure demotion rule is written down
• v1 Notion page marked superseded and pointing at the repo file

Follow-ups (not blocking)

• Branch protection with the six required checks
• GitHub merge queue (makes freshness structural)
• Scheduled workflow implementing the demotion rule
• Retire the agent-completion/truth-gate apparatus (~7,400 lines) — separate PR

[linear-code]

GRV-336

[github-actions]

👋 Thanks for opening this issue! It has been automatically labeled for triage.

[coderabbitai]

🔗 Related PRs

#277 - Vercel remediation complete: waitUntil adoption + active middleware + @vercel/functions package (resolves three user-defined outcomes; 16-agent verification-gate consolidated PASS on full matrix) [closed]
#404 - fix(web): sync package-lock with @vercel/functions (unblocks #277 auto-merge) [merged]
#411 - ci: add agentic verification loop workflow and refactor state log [merged]
#872 - ci: enforce deterministic agent completion truth gate [merged]

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