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/supports-hyperlinks/browser.js

@@ -0,0 +1,8 @@
+'use strict';
+module.exports = {
+	stdin: false,
+	stderr: false,
+	supportsHyperlink: function () { // eslint-disable-line object-shorthand
+		return false;
+	}
+};