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/components/build/footer-message-control/index.native.js

@@ -0,0 +1,28 @@
+"use strict";
+
+var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault");
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = void 0;
+var _react = require("react");
+var _element = require("@wordpress/element");
+var _footerMessageCell = _interopRequireDefault(require("../mobile/bottom-sheet/footer-message-cell"));
+/**
+ * WordPress dependencies
+ */
+
+/**
+ * Internal dependencies
+ */
+
+function FooterMessageControl({
+  ...props
+}) {
+  return (0, _react.createElement)(_footerMessageCell.default, {
+    ...props
+  });
+}
+var _default = (0, _element.memo)(FooterMessageControl);
+exports.default = _default;
+//# sourceMappingURL=index.native.js.map

node_modules/@wordpress/components/build/footer-message-control/index.native.js.map

@@ -0,0 +1 @@
+{"version":3,"names":["_element","require","_footerMessageCell","_interopRequireDefault","FooterMessageControl","props","_react","createElement","default","_default","memo","exports"],"sources":["@wordpress/components/src/footer-message-control/index.native.js"],"sourcesContent":["/**\n * WordPress dependencies\n */\nimport { memo } from '@wordpress/element';\n/**\n * Internal dependencies\n */\nimport FooterMessageCell from '../mobile/bottom-sheet/footer-message-cell';\n\nfunction FooterMessageControl( { ...props } ) {\n\treturn <FooterMessageCell { ...props } />;\n}\n\nexport default memo( FooterMessageControl );\n"],"mappings":";;;;;;;;AAGA,IAAAA,QAAA,GAAAC,OAAA;AAIA,IAAAC,kBAAA,GAAAC,sBAAA,CAAAF,OAAA;AAPA;AACA;AACA;;AAEA;AACA;AACA;;AAGA,SAASG,oBAAoBA,CAAE;EAAE,GAAGC;AAAM,CAAC,EAAG;EAC7C,OAAO,IAAAC,MAAA,CAAAC,aAAA,EAACL,kBAAA,CAAAM,OAAiB;IAAA,GAAMH;EAAK,CAAI,CAAC;AAC1C;AAAC,IAAAI,QAAA,GAEc,IAAAC,aAAI,EAAEN,oBAAqB,CAAC;AAAAO,OAAA,CAAAH,OAAA,GAAAC,QAAA"}