fix: PR idempotency checks open state, dedupe touchfiles, sync package.json

- Step 8 PR guard now checks state==OPEN so closed PRs don't prevent
  new PR creation (adversarial review finding)
- Remove duplicate ship-idempotency entry in E2E_TOUCHFILES
- Sync package.json version to 0.14.3.0

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

test/helpers/touchfiles.ts

@@ -82,7 +82,6 @@ export const E2E_TOUCHFILES: Record<string, string[]> = {
   'review-dashboard-via': ['ship/**', 'scripts/resolvers/review.ts', 'codex/**', 'autoplan/**', 'land-and-deploy/**'],
   'ship-plan-completion': ['ship/**', 'scripts/gen-skill-docs.ts'],
   'ship-plan-verification': ['ship/**', 'scripts/gen-skill-docs.ts'],
-  'ship-idempotency':      ['ship/**', 'scripts/resolvers/utility.ts'],
 
   // Retro
   'retro':             ['retro/**'],