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/char-regex/README.md

@@ -0,0 +1,27 @@
+# Char Regex [![Travis CI Build Status](https://img.shields.io/travis/com/Richienb/char-regex/master.svg?style=for-the-badge)](https://travis-ci.com/Richienb/char-regex)
+
+A regex to match any full character, considering weird character ranges. Tested on every single emoji and unicode character. Based on the Lodash implementation.
+
+[![NPM Badge](https://nodei.co/npm/char-regex.png)](https://npmjs.com/package/char-regex)
+
+## Install
+
+```sh
+npm install char-regex
+```
+
+## Usage
+
+```js
+const charRegex = require("char-regex");
+
+"❤️👊🏽".match(/./);
+//=> ["", "", "", "", "", "", ""]
+
+"❤️👊🏽".match(charRegex());
+//=> ["❤️", "👊🏽"]
+```
+
+## API
+
+### charRegex()