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/axobject-query/lib/util/iteratorProxy.js

@@ -0,0 +1,33 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = void 0;
+// eslint-disable-next-line no-unused-vars
+function iteratorProxy() {
+  var values = this;
+  var index = 0;
+  var iter = {
+    '@@iterator': function iterator() {
+      return iter;
+    },
+    next: function next() {
+      if (index < values.length) {
+        var value = values[index];
+        index = index + 1;
+        return {
+          done: false,
+          value: value
+        };
+      } else {
+        return {
+          done: true
+        };
+      }
+    }
+  };
+  return iter;
+}
+var _default = iteratorProxy;
+exports.default = _default;