fix: prevent asset conflicts between React and Grid.js versions

Add coexistence checks to all enqueue methods to prevent loading
both React and Grid.js assets simultaneously.

Changes:
- ReactAdmin.php: Only enqueue React assets when ?react=1
- Init.php: Skip Grid.js when React active on admin pages
- Form.php, Coupon.php, Access.php: Restore classic assets when ?react=0
- Customer.php, Product.php, License.php: Add coexistence checks

Now the toggle between Classic and React versions works correctly.

Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

node_modules/playwright/lib/agents/copilot-setup-steps.yml

@@ -0,0 +1,34 @@
+name: "Copilot Setup Steps"
+
+on:
+  workflow_dispatch:
+  push:
+    paths:
+      - .github/workflows/copilot-setup-steps.yml
+  pull_request:
+    paths:
+      - .github/workflows/copilot-setup-steps.yml
+
+jobs:
+  copilot-setup-steps:
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: read
+
+    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
+
+    # Customize this step as needed
+    - name: Build application
+      run: npx run build