ci(acceptance): add hang-proof Playwright smoke gate

Re-establishes acceptance-level CI signal for 4.x, which currently runs only
unit/rest/runner suites while the disabled acceptance workflow still targets
3.x + docker WebDriverIO.

- test/acceptance/codecept.Playwright.smoke.js: an explicit allowlist
  (els/session/within) of acceptance tests that pass reliably on the 4.x
  promise core. 52 passed / 2 skipped / 0 failed across three consecutive
  local runs.
- .github/workflows/acceptance-smoke.yml: runs the smoke suite on every PR
  with both timeout-minutes: 20 and an outer `timeout 600` (exit 124 = hang =
  release blocker), installs Chromium, boots the PHP test app, and uploads
  test/acceptance/output/ on failure.

The allowlist only grows: when a promise-core fix makes an excluded file pass,
move it into the glob in the same PR. Long-term goal is to gate on the full
codecept.Playwright.js and delete this config.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: DavertMik

.github/workflows/acceptance-smoke.yml

@@ -0,0 +1,52 @@
+name: Acceptance smoke
+
+on:
+  push:
+    branches:
+      - 4.x
+  pull_request:
+    branches:
+      - '**'
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  acceptance-smoke:
+    name: Acceptance smoke (Playwright)
+    runs-on: ubuntu-22.04
+    timeout-minutes: 20
+
+    strategy:
+      matrix:
+        node-version: [20.x]
+
+    steps:
+      - uses: actions/checkout@v6
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v6
+        with:
+          node-version: ${{ matrix.node-version }}
+      - run: npm i
+        env:
+          PUPPETEER_SKIP_CHROMIUM_DOWNLOAD: true
+      - name: Install Chromium
+        run: npx playwright install --with-deps chromium
+      - name: Start test app server
+        run: nohup npm run test-app:start &
+      - name: Wait for test app server
+        run: |
+          for i in {1..20}; do
+            curl -sf http://127.0.0.1:8000/ && break
+            sleep 1
+          done
+      - name: Run acceptance smoke suite (hang-proof)
+        run: timeout 600 ./bin/codecept.js run --config test/acceptance/codecept.Playwright.smoke.js
+      - name: Upload acceptance output on failure
+        if: failure()
+        uses: actions/upload-artifact@v4
+        with:
+          name: acceptance-smoke-output
+          path: test/acceptance/output/
+          if-no-files-found: ignore

test/acceptance/codecept.Playwright.smoke.js

@@ -0,0 +1,11 @@
+import { config as base } from './codecept.Playwright.js'
+
+// Allowlist of acceptance tests known to pass reliably on the 4.x promise core.
+// As promise-core fixes land and a file in plans/002-failing-acceptance.md
+// starts passing, move it into this glob. The long-term goal is to delete this
+// config and gate on the full codecept.Playwright.js.
+export const config = {
+  ...base,
+  tests: './{els,session,within}_test.js',
+  name: 'acceptance-smoke',
+}