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/css-select/lib/esm/helpers/cache.js

@@ -0,0 +1,41 @@
+import { getElementParent } from "./querying.js";
+/**
+ * Some selectors such as `:contains` and (non-relative) `:has` will only be
+ * able to match elements if their parents match the selector (as they contain
+ * a subset of the elements that the parent contains).
+ *
+ * This function wraps the given `matches` function in a function that caches
+ * the results of the parent elements, so that the `matches` function only
+ * needs to be called once for each subtree.
+ */
+export function cacheParentResults(next, { adapter, cacheResults }, matches) {
+    if (cacheResults === false || typeof WeakMap === "undefined") {
+        return (elem) => next(elem) && matches(elem);
+    }
+    // Use a cache to avoid re-checking children of an element.
+    // @ts-expect-error `Node` is not extending object
+    const resultCache = new WeakMap();
+    function addResultToCache(elem) {
+        const result = matches(elem);
+        resultCache.set(elem, result);
+        return result;
+    }
+    return function cachedMatcher(elem) {
+        if (!next(elem))
+            return false;
+        if (resultCache.has(elem)) {
+            return resultCache.get(elem);
+        }
+        // Check all of the element's parents.
+        let node = elem;
+        do {
+            const parent = getElementParent(node, adapter);
+            if (parent === null) {
+                return addResultToCache(elem);
+            }
+            node = parent;
+        } while (!resultCache.has(node));
+        return resultCache.get(node) && addResultToCache(elem);
+    };
+}
+//# sourceMappingURL=cache.js.map