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/wait-on/.eslintrc.js

@@ -0,0 +1,20 @@
+module.exports = {
+  env: {
+    mocha: true
+  },
+  plugins: ['chai-friendly'],
+  extends: ['standard', 'prettier'],
+  root: true,
+  rules: {
+    'no-use-before-define': 'off',
+    'no-unused-vars': [
+      'error',
+      {
+        varsIgnorePattern: 'should|expect'
+      }
+    ],
+    // disable the original no-unused-expressions use chai-friendly
+    'no-unused-expressions': 'off',
+    'chai-friendly/no-unused-expressions': 'error'
+  }
+};