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/bare-path/README.md

@@ -0,0 +1,19 @@
+# bare-path
+
+Path manipulation library for JavaScript.
+
+```
+npm i bare-path
+```
+
+## Usage
+
+``` js
+const path = require('bare-path')
+
+path.join('foo', 'bar') // foo/bar on posix, foo\bar on windows
+```
+
+## License
+
+Apache-2.0