ci: update peptide-e2e reusable-workflow ref to peptide-repo org

Reusable workflow `uses:` refs do not follow GitHub transfer redirects.
Update owner string from peptiderepo to peptide-repo post org-migration.

Agent-Session: fix-e2e-ref-20260617

.github/workflows/deploy.yml

@@ -19,7 +19,7 @@ jobs:
   deploy:
     name: Deploy (shared pipeline)
     needs: ci
-    uses: peptiderepo/peptide-e2e/.github/workflows/deploy-app.yml@main
+    uses: peptide-repo/peptide-e2e/.github/workflows/deploy-app.yml@main
     with:
       target_path: wp-content/plugins/prautoblogger
     secrets: inherit