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/button/deprecated.js

@@ -0,0 +1,38 @@
+import { createElement } from "react";
+/**
+ * External dependencies
+ */
+
+/**
+ * WordPress dependencies
+ */
+import deprecated from '@wordpress/deprecated';
+import { forwardRef } from '@wordpress/element';
+
+/**
+ * Internal dependencies
+ */
+import Button from '.';
+function UnforwardedIconButton({
+  label,
+  labelPosition,
+  size,
+  tooltip,
+  ...props
+}, ref) {
+  deprecated('wp.components.IconButton', {
+    since: '5.4',
+    alternative: 'wp.components.Button',
+    version: '6.2'
+  });
+  return createElement(Button, {
+    ...props,
+    ref: ref,
+    tooltipPosition: labelPosition,
+    iconSize: size,
+    showTooltip: tooltip !== undefined ? !!tooltip : undefined,
+    label: tooltip || label
+  });
+}
+export default forwardRef(UnforwardedIconButton);
+//# sourceMappingURL=deprecated.js.map