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/acorn-globals/README.md

@@ -0,0 +1,81 @@
+# acorn-globals
+
+Detect global variables in JavaScript using acorn
+
+[Get supported acorn-globals with the Tidelift Subscription](https://tidelift.com/subscription/pkg/npm-acorn_globals?utm_source=npm-acorn-globals&utm_medium=referral&utm_campaign=readme)
+
+[![Build Status](https://img.shields.io/github/workflow/status/ForbesLindesay/acorn-globals/Publish%20Canary/master?style=for-the-badge)](https://github.com/ForbesLindesay/acorn-globals/actions?query=workflow%3APublish%20Canary+branch%3Amaster)
+[![Rolling Versions](https://img.shields.io/badge/Rolling%20Versions-Enabled-brightgreen?style=for-the-badge)](https://rollingversions.com/ForbesLindesay/acorn-globals)
+[![NPM version](https://img.shields.io/npm/v/acorn-globals?style=for-the-badge)](https://www.npmjs.com/package/acorn-globals)
+
+## Installation
+
+    npm install acorn-globals
+
+## Usage
+
+detect.js
+
+```js
+var fs = require('fs');
+var detect = require('acorn-globals');
+
+var src = fs.readFileSync(__dirname + '/input.js', 'utf8');
+
+var scope = detect(src);
+console.dir(scope);
+```
+
+input.js
+
+```js
+var x = 5;
+var y = 3, z = 2;
+
+w.foo();
+w = 2;
+
+RAWR=444;
+RAWR.foo();
+
+BLARG=3;
+
+foo(function () {
+    var BAR = 3;
+    process.nextTick(function (ZZZZZZZZZZZZ) {
+        console.log('beep boop');
+        var xyz = 4;
+        x += 10;
+        x.zzzzzz;
+        ZZZ=6;
+    });
+    function doom () {
+    }
+    ZZZ.foo();
+
+});
+
+console.log(xyz);
+```
+
+output:
+
+```
+$ node example/detect.js
+[ { name: 'BLARG', nodes: [ [Object] ] },
+  { name: 'RAWR', nodes: [ [Object], [Object] ] },
+  { name: 'ZZZ', nodes: [ [Object], [Object] ] },
+  { name: 'console', nodes: [ [Object], [Object] ] },
+  { name: 'foo', nodes: [ [Object] ] },
+  { name: 'process', nodes: [ [Object] ] },
+  { name: 'w', nodes: [ [Object], [Object] ] },
+  { name: 'xyz', nodes: [ [Object] ] } ]
+```
+
+## Security contact information
+
+To report a security vulnerability, please use the [Tidelift security contact](https://tidelift.com/security). Tidelift will coordinate the fix and disclosure.
+
+## License
+
+  MIT