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/jsx-ast-utils/lib/values/Literal.js

@@ -0,0 +1,27 @@
+'use strict';
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = extractValueFromLiteral;
+/**
+ * Extractor function for a Literal type value node.
+ *
+ * @param - value - AST Value object with type `Literal`
+ * @returns { String|Boolean } - The extracted value converted to correct type.
+ */
+function extractValueFromLiteral(value) {
+  var extractedValue = value.value;
+
+
+  var normalizedStringValue = typeof extractedValue === 'string' && extractedValue.toLowerCase();
+  if (normalizedStringValue === 'true') {
+    return true;
+  }
+
+  if (normalizedStringValue === 'false') {
+    return false;
+  }
+
+  return extractedValue;
+}