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/@sentry/utils/esm/async.js

@@ -0,0 +1,13 @@
+/**
+ * Consumes the promise and logs the error when it rejects.
+ * @param promise A promise to forget.
+ */
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+export function forget(promise) {
+    void promise.then(null, function (e) {
+        // TODO: Use a better logging mechanism
+        // eslint-disable-next-line no-console
+        console.error(e);
+    });
+}
+//# sourceMappingURL=async.js.map