feat: add scheduled Playwright tests workflow with shard approach

.github/workflows/scheduled-playwright.yml

@@ -0,0 +1,121 @@
+name: 'Scheduled Playwright Tests'
+
+on:
+  schedule:
+    # Run daily at 06:00 UTC
+    - cron: '0 6 * * *'
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: scheduled-playwright
+  cancel-in-progress: false
+
+jobs:
+  playwright:
+    name: 'Playwright (${{ matrix.shard }}/8)'
+    runs-on: ubuntu-latest-8-cores
+    timeout-minutes: 60
+    strategy:
+      fail-fast: false
+      max-parallel: 4
+      matrix:
+        shard: [1, 2, 3, 4, 5, 6, 7, 8]
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Install Node.js 22.x
+        uses: actions/setup-node@v4
+        with:
+          node-version: 22.x
+
+      - name: Get yarn cache directory path
+        id: yarn-cache-dir-path
+        run: echo "dir=$(yarn cache dir)" >> "$GITHUB_OUTPUT"
+        shell: bash
+
+      - name: Restore yarn cache
+        uses: actions/cache@v4
+        with:
+          path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
+          key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-yarn-
+
+      - name: Set Yarn version
+        run: yarn policies set-version v1.22.22
+
+      - name: Yarn install
+        uses: nick-fields/retry@v3
+        env:
+          CUBESTORE_SKIP_POST_INSTALL: true
+        with:
+          max_attempts: 3
+          retry_on: error
+          retry_wait_seconds: 15
+          timeout_minutes: 20
+          command: yarn install --frozen-lockfile
+
+      - name: Install Playwright browsers
+        run: npx playwright install --with-deps
+
+      - name: Build
+        run: |
+          yarn build
+          yarn tsc
+
+      - name: Run Playwright tests (shard ${{ matrix.shard }}/8)
+        run: npx playwright test --shard=${{ matrix.shard }}/8 --reporter=blob
+
+      - name: Upload blob report
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: blob-report-${{ matrix.shard }}
+          path: blob-report/
+          retention-days: 1
+
+  merge-reports:
+    name: 'Merge Playwright Reports'
+    if: always()
+    needs: [playwright]
+    runs-on: ubuntu-24.04
+    timeout-minutes: 10
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Install Node.js 22.x
+        uses: actions/setup-node@v4
+        with:
+          node-version: 22.x
+
+      - name: Download blob reports
+        uses: actions/download-artifact@v4
+        with:
+          pattern: blob-report-*
+          path: all-blob-reports
+          merge-multiple: true
+
+      - name: Merge reports
+        run: npx playwright merge-reports --reporter html ./all-blob-reports
+
+      - name: Upload merged HTML report
+        uses: actions/upload-artifact@v4
+        with:
+          name: playwright-report
+          path: playwright-report/
+          retention-days: 14
+
+      - name: Slack Failure
+        if: ${{ always() && needs.playwright.result == 'failure' }}
+        uses: voxmedia/github-action-slack-notify-build@v1
+        with:
+          channel: oss-ci
+          status: FAILED
+          color: danger
+        env:
+          SLACK_BOT_TOKEN: ${{ secrets.SLACK_BOT_TOKEN }}