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/@wordpress/eslint-plugin/utils/get-translate-function-name.js

@@ -0,0 +1,17 @@
+/**
+ * Get the actual translation function name from a CallExpression callee.
+ *
+ * Returns the "__" part from __ or i18n.__.
+ *
+ * @param {Object} callee
+ * @return {string} Function name.
+ */
+function getTranslateFunctionName( callee ) {
+	return callee.property && callee.property.name
+		? callee.property.name
+		: callee.name;
+}
+
+module.exports = {
+	getTranslateFunctionName,
+};