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-react/lib/util/pragma.d.ts

@@ -0,0 +1,16 @@
+/**
+ * @param {Context} context
+ * @returns {string}
+ */
+export function getCreateClassFromContext(context: Context): string;
+/**
+ * @param {Context} context
+ * @returns {string}
+ */
+export function getFragmentFromContext(context: Context): string;
+/**
+ * @param {Context} context
+ * @returns {string}
+ */
+export function getFromContext(context: Context): string;
+//# sourceMappingURL=pragma.d.ts.map