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/highlight-words-core/README.md

@@ -0,0 +1,54 @@
+Utility functions shared by [`react-highlight-words`](https://github.com/bvaughn/react-highlight-words) and [`react-native-highlight-words`](https://github.com/clauderic/react-native-highlight-words).
+
+---
+### 🎉 [Become a sponsor](https://github.com/sponsors/bvaughn/) or ☕ [Buy me a coffee](http://givebrian.coffee/)
+---
+
+## API
+
+The primary API for this package is a function exported as `findAll`. This method searches a string of text for a set of search terms and returns an array of "chunks" that describe the matches found.
+
+Each "chunk" is an object consisting of a pair of indices (`chunk.start` and `chunk.end`) and a boolean specfifying whether the chunk is a match (`chunk.highlight`). For example:
+
+```js
+import { findAll } from "highlight-words-core";
+
+const textToHighlight = "This is some text to highlight.";
+const searchWords = ["This", "i"];
+
+const chunks = findAll({
+  searchWords,
+  textToHighlight
+});
+
+const highlightedText = chunks
+  .map(chunk => {
+    const { end, highlight, start } = chunk;
+    const text = textToHighlight.substr(start, end - start);
+    if (highlight) {
+      return `<mark>${text}</mark>`;
+    } else {
+      return text;
+    }
+  })
+  .join("");
+```
+
+[Run this example on Code Sandbox.](https://codesandbox.io/s/ykwrzrl6wx)
+
+### `findAll`
+
+The `findAll` function accepts several parameters, although only the `searchWords` array and `textToHighlight` string are required.
+
+| Parameter | Required? | Type | Description |
+| --- | :---: | --- | --- |
+| autoEscape |  | `boolean` | Escape special regular expression characters |
+| caseSensitive |  | `boolean` | Search should be case sensitive |
+| findChunks |  | `Function` | Custom find function (advanced) |
+| sanitize |  | `Function` | Custom sanitize function (advanced) |
+| searchWords | ✅ | `Array<string>` | Array of words to search for |
+| textToHighlight | ✅ | `string` | Text to search and highlight |
+
+
+## License
+MIT License - fork, modify and use however you want.