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/@wordpress/components/build-module/v-stack/hook.js

@@ -0,0 +1,21 @@
+/**
+ * Internal dependencies
+ */
+
+import { useContextSystem } from '../context';
+import { useHStack } from '../h-stack';
+export function useVStack(props) {
+  const {
+    expanded = false,
+    alignment = 'stretch',
+    ...otherProps
+  } = useContextSystem(props, 'VStack');
+  const hStackProps = useHStack({
+    direction: 'column',
+    expanded,
+    alignment,
+    ...otherProps
+  });
+  return hStackProps;
+}
+//# sourceMappingURL=hook.js.map