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/grid/component.js

@@ -0,0 +1,43 @@
+import { createElement } from "react";
+/**
+ * External dependencies
+ */
+
+/**
+ * Internal dependencies
+ */
+
+import { contextConnect } from '../context';
+import { View } from '../view';
+import useGrid from './hook';
+function UnconnectedGrid(props, forwardedRef) {
+  const gridProps = useGrid(props);
+  return createElement(View, {
+    ...gridProps,
+    ref: forwardedRef
+  });
+}
+
+/**
+ * `Grid` is a primitive layout component that can arrange content in a grid configuration.
+ *
+ * ```jsx
+ * import {
+ * 	__experimentalGrid as Grid,
+ * 	__experimentalText as Text
+ * } from `@wordpress/components`;
+ *
+ * function Example() {
+ * 	return (
+ * 		<Grid columns={ 3 }>
+ * 			<Text>Code</Text>
+ * 			<Text>is</Text>
+ * 			<Text>Poetry</Text>
+ * 		</Grid>
+ * 	);
+ * }
+ * ```
+ */
+export const Grid = contextConnect(UnconnectedGrid, 'Grid');
+export default Grid;
+//# sourceMappingURL=component.js.map