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/rxjs/dist/cjs/ajax/index.js

@@ -0,0 +1,11 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.AjaxResponse = exports.AjaxTimeoutError = exports.AjaxError = exports.ajax = void 0;
+var ajax_1 = require("../internal/ajax/ajax");
+Object.defineProperty(exports, "ajax", { enumerable: true, get: function () { return ajax_1.ajax; } });
+var errors_1 = require("../internal/ajax/errors");
+Object.defineProperty(exports, "AjaxError", { enumerable: true, get: function () { return errors_1.AjaxError; } });
+Object.defineProperty(exports, "AjaxTimeoutError", { enumerable: true, get: function () { return errors_1.AjaxTimeoutError; } });
+var AjaxResponse_1 = require("../internal/ajax/AjaxResponse");
+Object.defineProperty(exports, "AjaxResponse", { enumerable: true, get: function () { return AjaxResponse_1.AjaxResponse; } });
+//# sourceMappingURL=index.js.map

node_modules/rxjs/dist/cjs/ajax/index.js.map

@@ -0,0 +1 @@
+{"version":3,"file":"index.js","sourceRoot":"","sources":["../../../src/ajax/index.ts"],"names":[],"mappings":";;;AAAA,8CAA6C;AAApC,4FAAA,IAAI,OAAA;AACb,kDAAsE;AAA7D,mGAAA,SAAS,OAAA;AAAE,0GAAA,gBAAgB,OAAA;AACpC,8DAA6D;AAApD,4GAAA,YAAY,OAAA"}