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/eslint-plugin-jest/lib/processors/snapshot-processor.js

@@ -0,0 +1,20 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.preprocess = exports.postprocess = exports.meta = void 0;
+var _package = require("../../package.json");
+// https://eslint.org/docs/developer-guide/working-with-plugins#processors-in-plugins
+// https://github.com/typescript-eslint/typescript-eslint/issues/808
+
+const meta = exports.meta = {
+  name: _package.name,
+  version: _package.version
+};
+const preprocess = source => [source];
+exports.preprocess = preprocess;
+const postprocess = messages =>
+// snapshot files should only be linted with snapshot specific rules
+messages[0].filter(message => message.ruleId === 'jest/no-large-snapshots');
+exports.postprocess = postprocess;