idd-skill: Instructions file for GitHub Copilot

IDD — Pre-Merge Conditions Phase (F1–F2)

Read after the E-phase branch-sync check confirms no sync is required, or when returning to merge-gate checks after a sync cycle. Covers F1 (read-only branch-state check) and F2 (pre-merge checklist).

This phase's GitHub Copilot advisory review gate depends on GitHub review state, not the local CLI, so follow it under any local agent.

F2's merge-gate timing defaults are named in IDD policy constants — canonical, not an override.

Before any F-phase mutating action, apply the shared claim revalidation gate.

After a forced handoff on an open PR, the successor must rebuild review state through E1/E2 under its own {claim-id} before merge-bound routing continues — a live status digest or prior-claim marker is UI/audit context only, and cannot satisfy review currency, claim ownership, advisory wait, or CI gates.

When all F2 conditions are satisfied, proceed to idd-merge-handoff.instructions.md.

F1 — Final branch-state check

Read the current branch state. When helper runtime is enabled, call: idd-branch-conflict-state --pr {pr-number}

Otherwise read the state directly:

gh pr view {pr-number} --json mergeable,mergeStateStatus,headRefOid,baseRefName
git fetch --no-tags origin {base-branch}
git merge-base {pr-head-sha} FETCH_HEAD
# vs: git rev-parse FETCH_HEAD; mismatch/unresolvable = baseAdvancedSinceMergeBase: true below (best-effort)

This check is read-only — F1 does not rebase, merge, or push.

• clean (mergeable is MERGEABLE and mergeStateStatus is CLEAN) or behind-no-conflict when no up-to-date-head policy applies: proceed to F2. clean is conflict-freeness only — if baseAdvancedSinceMergeBase: true, prefer a fresh CI result over an old green check.
• behind-no-conflict when branch protection or recorded policy requires an up-to-date head, or unreadable/ambiguous (fails closed), or content-conflict (mergeable is CONFLICTING): return to the E-phase branch-sync check in idd-review-triage.instructions.md, first setting Phase: F1 sync-required, the branch state in Open blockers, and Next action: E-phase branch-sync on the digest.
• computing (syncRecommendation is recheck): mergeable is UNKNOWN / null because GitHub has not settled mergeability yet (common right after E1 posts its watermark/baseline) — transient, not terminal. Do not hold; re-poll after a short wait (default: 3 attempts, a few seconds apart), then route by the first settled result. Only if still computing/unknown after the budget, fall through to the terminal hold below.
• dirty (mergeStateStatus is DIRTY) or unknown: hold; post a PR comment documenting the branch state and stop. A maintainer must clear the hold.