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/eslint-plugin-import/docs/rules/dynamic-import-chunkname.md

@@ -0,0 +1,134 @@
+# import/dynamic-import-chunkname
+
+💡 This rule is manually fixable by [editor suggestions](https://eslint.org/docs/latest/use/core-concepts#rule-suggestions).
+
+<!-- end auto-generated rule header -->
+
+This rule reports any dynamic imports without a webpackChunkName specified in a leading block comment in the proper format.
+
+This rule enforces naming of webpack chunks in dynamic imports. When you don't explicitly name chunks, webpack will autogenerate chunk names that are not consistent across builds, which prevents long-term browser caching.
+
+## Rule Details
+
+This rule runs against `import()` by default, but can be configured to also run against an alternative dynamic-import function, e.g. 'dynamicImport.'
+You can also configure the regex format you'd like to accept for the webpackChunkName - for example, if we don't want the number 6 to show up in our chunk names:
+
+ ```javascript
+{
+  "import/dynamic-import-chunkname": [2, {
+    importFunctions: ["dynamicImport"],
+    webpackChunknameFormat: "[a-zA-Z0-57-9-/_]+",
+    allowEmpty: false
+  }]
+}
+```
+
+### invalid
+
+The following patterns are invalid:
+
+```javascript
+// no leading comment
+import('someModule');
+
+// incorrectly formatted comment
+import(
+  /*webpackChunkName:"someModule"*/
+  'someModule',
+);
+import(
+  /* webpackChunkName : "someModule" */
+  'someModule',
+);
+
+// chunkname contains a 6 (forbidden by rule config)
+import(
+  /* webpackChunkName: "someModule6" */
+  'someModule',
+);
+
+// invalid syntax for webpack comment
+import(
+  /* totally not webpackChunkName: "someModule" */
+  'someModule',
+);
+
+// single-line comment, not a block-style comment
+import(
+  // webpackChunkName: "someModule"
+  'someModule',
+);
+
+// chunk names are disallowed when eager mode is set
+import(
+  /* webpackMode: "eager" */
+  /* webpackChunkName: "someModule" */
+  'someModule',
+)
+```
+
+### valid
+
+The following patterns are valid:
+
+```javascript
+  import(
+    /* webpackChunkName: "someModule" */
+    'someModule',
+  );
+  import(
+    /* webpackChunkName: "someOtherModule12345789" */
+    'someModule',
+  );
+  import(
+    /* webpackChunkName: "someModule" */
+    /* webpackPrefetch: true */
+    'someModule',
+  );
+  import(
+    /* webpackChunkName: "someModule", webpackPrefetch: true */
+    'someModule',
+  );
+
+  // using single quotes instead of double quotes
+  import(
+    /* webpackChunkName: 'someModule' */
+    'someModule',
+  );
+```
+
+### `allowEmpty: true`
+
+If you want to allow dynamic imports without a webpackChunkName, you can set `allowEmpty: true` in the rule config. This will allow dynamic imports without a leading comment, or with a leading comment that does not contain a webpackChunkName.
+
+Given `{ "allowEmpty": true }`:
+
+<!-- markdownlint-disable-next-line MD024 -- duplicate header -->
+### valid
+
+The following patterns are valid:
+
+```javascript
+import('someModule');
+
+import(
+  /* webpackChunkName: "someModule" */
+  'someModule',
+);
+```
+<!-- markdownlint-disable-next-line MD024 -- duplicate header -->
+### invalid
+
+The following patterns are invalid:
+
+```javascript
+// incorrectly formatted comment
+import(
+  /*webpackChunkName:"someModule"*/
+  'someModule',
+);
+```
+
+## When Not To Use It
+
+If you don't care that webpack will autogenerate chunk names and may blow up browser caches and bundle size reports.