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/@svgr/core/README.md

@@ -0,0 +1,56 @@
+# @svgr/core
+
+[![Build Status][build-badge]][build]
+[![version][version-badge]][package]
+[![MIT License][license-badge]][license]
+
+Node API of SVGR.
+
+```
+npm install @svgr/core
+```
+
+## Usage
+
+```js
+import { transform } from '@svgr/core'
+
+const svgCode = `
+<svg xmlns="http://www.w3.org/2000/svg"
+  xmlns:xlink="http://www.w3.org/1999/xlink">
+  <rect x="10" y="10" height="100" width="100"
+    style="stroke:#ff0000; fill: #0000ff"/>
+</svg>
+`
+
+transform(svgCode, { icon: true }, { componentName: 'MyComponent' }).then(
+  (jsCode) => {
+    console.log(jsCode)
+  },
+)
+```
+
+Use `svgr.sync(code, config, state)` if you would like to use sync version.
+
+### Plugins
+
+By default `@svgr/core` doesn't include any plugin, if you want them, you have to install them and include them in config.
+
+```js
+svgr(svgCode, {
+  plugins: ['@svgr/plugin-svgo', '@svgr/plugin-jsx', '@svgr/plugin-prettier'],
+}).then((jsCode) => {
+  console.log(jsCode)
+})
+```
+
+## License
+
+MIT
+
+[build-badge]: https://img.shields.io/travis/smooth-code/svgr.svg?style=flat-square
+[build]: https://travis-ci.org/smooth-code/svgr
+[version-badge]: https://img.shields.io/npm/v/@svgr/core.svg?style=flat-square
+[package]: https://www.npmjs.com/package/@svgr/core
+[license-badge]: https://img.shields.io/npm/l/@svgr/core.svg?style=flat-square
+[license]: https://github.com/smooth-code/svgr/blob/master/LICENSE