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/icss-utils/CHANGELOG.md

@@ -0,0 +1,30 @@
+# Change Log
+
+All notable changes to this project will be documented in this file.
+This project adheres to [Semantic Versioning](http://semver.org/).
+
+## [5.1.0] - 2020-11-19
+
+### Features
+
+- feat: support at-rule versions of `import`/`export`
+
+## [5.0.0] - 2020-10-12
+
+### BREAKING CHANGE
+
+- minimum supported `postcss` version is `^8.1.0`
+
+### Fixes
+
+- minimum supported `Node.js` version is `^10 || ^12 || >= 14`
+- compatibility with PostCSS 8
+
+## [5.0.0-rc.0] - 2020-09-21
+
+### BREAKING CHANGE
+
+- minimum supported `Node.js` version is `>= 10.13.0 || >= 12.13.0 || >= 14`
+- minimum supported `postcss` version is `^8.0.0`
+- `postcss` was moved to `peerDependencies`, you need to install `postcss` in your project before use the plugin
+- you need to pass `postcss` API to using `createICSSRules` (third argument)