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/table/dist/src/stringifyTableData.js

@@ -0,0 +1,13 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.stringifyTableData = void 0;
+const utils_1 = require("./utils");
+const stringifyTableData = (rows) => {
+    return rows.map((cells) => {
+        return cells.map((cell) => {
+            return (0, utils_1.normalizeString)(String(cell));
+        });
+    });
+};
+exports.stringifyTableData = stringifyTableData;
+//# sourceMappingURL=stringifyTableData.js.map