chore(ci): add job to test against a saas instance

.github/workflows/test.yml

@@ -1,5 +1,7 @@
 on:
     pull_request:
+    workflow_dispatch:
+
 name: test
 jobs:
     eslint:
@@ -68,3 +70,22 @@ jobs:
           name: playwright-report-${{ matrix.instance.compose-service }} 
           path: test-results/
           retention-days: 7
+    test-saas:
+      timeout-minutes: 15
+      runs-on: ubuntu-latest
+      concurrency: saas # only allow one job at a time
+      env:
+        APP_URL: ${{ secrets.SAAS_APP_URL }}
+        SHOPWARE_ADMIN_USERNAME: ${{ secrets.SAAS_SHOPWARE_ADMIN_USERNAME }}
+        SHOPWARE_ADMIN_PASSWORD: ${{ secrets.SAAS_SHOPWARE_ADMIN_PASSWORD }}
+      steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: lts/*
+      - name: Install dependencies
+        run: npm ci
+      - name: Install Playwright Browsers
+        run: npx playwright install --with-deps
+      - name: Run Playwright tests
+        run: npx playwright test --repeat-each 2