fix(run-completion): make PR finalization idempotent

services/gateway/CHANGELOG.md

@@ -4,6 +4,7 @@ All notable changes to `@farmslot/gateway` are tracked here.
 
 ## Unreleased
 
+- fix(run-completion): reconcile merged and already-ready PRs without replaying `gh pr ready`, and report closed-unmerged PRs explicitly.
 - fix(run-engine): project publication review counts against the current prepared package, so an older passing review is shown as stale instead of contradicting the publish cockpit.
 - fix(runners): require a task-scoped signal or exact runner hook before cold dispatch or a warm-session handoff starts monitoring, recreate the persisted primary worker target before restart delivery, validate the exact Claude settings artifact even when an older node installer exits successfully, never reuse a pre-replay task signal, and never repair failed dispatch by matching runner prose.
 - feat(run-engine): ready-gate and package-refresh soft-chip probe for behind-main count + non-destructive merge-tree conflicts (`behindMain`, `mergeConflicts`) so operators see staleness before more review loops — never auto-rebases mid-loop.

services/gateway/src/run-completion/pr-publication.test.ts

@@ -5,9 +5,26 @@ import {
   paginatedPrCommentOutputContainsRun,
   prCommentBelongsToRun,
   prCommentIdentityMarker,
+  resolvePrReadyAction,
   shouldPostWorkerReportComment,
 } from './pr-publication.js';
 
+test('PR ready action is idempotent across lifecycle states', () => {
+  assert.equal(
+    resolvePrReadyAction({ state: 'MERGED', isDraft: false, mergedAt: '2026-08-04T09:37:17Z' }),
+    'merged',
+  );
+  assert.equal(
+    resolvePrReadyAction({ state: 'OPEN', isDraft: false, mergedAt: null }),
+    'already-ready',
+  );
+  assert.equal(
+    resolvePrReadyAction({ state: 'OPEN', isDraft: true, mergedAt: null }),
+    'mark-ready',
+  );
+  assert.equal(resolvePrReadyAction({ state: 'CLOSED', isDraft: false, mergedAt: null }), 'closed');
+});
+
 test('PR comment identity is stable per run and supports legacy comments', () => {
   const runId = 'b26f39be-fb72-407b-ac77-47fdea539fb9';
 

services/gateway/src/run-completion/pr-publication.ts

@@ -298,7 +298,43 @@ export async function updatePRTitle(run: Run, ciRepo: string, prNumber: number):
 
 // ─── Mark PR ready for review ───
 
-export async function markPRReady(ciRepo: string, prNumber: number): Promise<void> {
+export type PrReadyResult = 'marked-ready' | 'already-ready' | 'merged';
+
+interface PrLifecycle {
+  state: 'OPEN' | 'CLOSED' | 'MERGED';
+  isDraft: boolean;
+  mergedAt: string | null;
+}
+
+export function resolvePrReadyAction(pr: PrLifecycle): PrReadyResult | 'closed' | 'mark-ready' {
+  if (pr.state === 'MERGED' || pr.mergedAt) return 'merged';
+  if (pr.state === 'CLOSED') return 'closed';
+  return pr.isDraft ? 'mark-ready' : 'already-ready';
+}
+
+export async function markPRReady(ciRepo: string, prNumber: number): Promise<PrReadyResult> {
+  const result = await ghRequest([
+    'pr',
+    'view',
+    String(prNumber),
+    '--repo',
+    ciRepo,
+    '--json',
+    'state,isDraft,mergedAt',
+  ]);
+  const action = resolvePrReadyAction(JSON.parse(result.stdout || '{}') as PrLifecycle);
+  if (action === 'merged') {
+    console.log(`[run-completion] PR #${prNumber} is already merged`);
+    return action;
+  }
+  if (action === 'already-ready') {
+    console.log(`[run-completion] PR #${prNumber} is already ready for review`);
+    return action;
+  }
+  if (action === 'closed') {
+    throw new Error(`PR #${prNumber} is closed without merging; it cannot be published`);
+  }
   await ghRequest(['pr', 'ready', String(prNumber), '--repo', ciRepo], { force: true });
   console.log(`[run-completion] marked PR #${prNumber} as ready for review`);
+  return 'marked-ready';
 }