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/@babel/plugin-transform-modules-amd/README.md

@@ -0,0 +1,19 @@
+# @babel/plugin-transform-modules-amd
+
+> This plugin transforms ES2015 modules to AMD
+
+See our website [@babel/plugin-transform-modules-amd](https://babeljs.io/docs/babel-plugin-transform-modules-amd) for more information.
+
+## Install
+
+Using npm:
+
+```sh
+npm install --save-dev @babel/plugin-transform-modules-amd
+```
+
+or using yarn:
+
+```sh
+yarn add @babel/plugin-transform-modules-amd --dev
+```