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/domutils/lib/legacy.d.ts

@@ -0,0 +1,79 @@
+import { AnyNode, Element } from "domhandler";
+import type { ElementType } from "domelementtype";
+/**
+ * An object with keys to check elements against. If a key is `tag_name`,
+ * `tag_type` or `tag_contains`, it will check the value against that specific
+ * value. Otherwise, it will check an attribute with the key's name.
+ *
+ * @category Legacy Query Functions
+ */
+export interface TestElementOpts {
+    tag_name?: string | ((name: string) => boolean);
+    tag_type?: string | ((name: string) => boolean);
+    tag_contains?: string | ((data?: string) => boolean);
+    [attributeName: string]: undefined | string | ((attributeValue: string) => boolean);
+}
+/**
+ * Checks whether a node matches the description in `options`.
+ *
+ * @category Legacy Query Functions
+ * @param options An object describing nodes to look for.
+ * @param node The element to test.
+ * @returns Whether the element matches the description in `options`.
+ */
+export declare function testElement(options: TestElementOpts, node: AnyNode): boolean;
+/**
+ * Returns all nodes that match `options`.
+ *
+ * @category Legacy Query Functions
+ * @param options An object describing nodes to look for.
+ * @param nodes Nodes to search through.
+ * @param recurse Also consider child nodes.
+ * @param limit Maximum number of nodes to return.
+ * @returns All nodes that match `options`.
+ */
+export declare function getElements(options: TestElementOpts, nodes: AnyNode | AnyNode[], recurse: boolean, limit?: number): AnyNode[];
+/**
+ * Returns the node with the supplied ID.
+ *
+ * @category Legacy Query Functions
+ * @param id The unique ID attribute value to look for.
+ * @param nodes Nodes to search through.
+ * @param recurse Also consider child nodes.
+ * @returns The node with the supplied ID.
+ */
+export declare function getElementById(id: string | ((id: string) => boolean), nodes: AnyNode | AnyNode[], recurse?: boolean): Element | null;
+/**
+ * Returns all nodes with the supplied `tagName`.
+ *
+ * @category Legacy Query Functions
+ * @param tagName Tag name to search for.
+ * @param nodes Nodes to search through.
+ * @param recurse Also consider child nodes.
+ * @param limit Maximum number of nodes to return.
+ * @returns All nodes with the supplied `tagName`.
+ */
+export declare function getElementsByTagName(tagName: string | ((name: string) => boolean), nodes: AnyNode | AnyNode[], recurse?: boolean, limit?: number): Element[];
+/**
+ * Returns all nodes with the supplied `className`.
+ *
+ * @category Legacy Query Functions
+ * @param className Class name to search for.
+ * @param nodes Nodes to search through.
+ * @param recurse Also consider child nodes.
+ * @param limit Maximum number of nodes to return.
+ * @returns All nodes with the supplied `className`.
+ */
+export declare function getElementsByClassName(className: string | ((name: string) => boolean), nodes: AnyNode | AnyNode[], recurse?: boolean, limit?: number): Element[];
+/**
+ * Returns all nodes with the supplied `type`.
+ *
+ * @category Legacy Query Functions
+ * @param type Element type to look for.
+ * @param nodes Nodes to search through.
+ * @param recurse Also consider child nodes.
+ * @param limit Maximum number of nodes to return.
+ * @returns All nodes with the supplied `type`.
+ */
+export declare function getElementsByTagType(type: ElementType | ((type: ElementType) => boolean), nodes: AnyNode | AnyNode[], recurse?: boolean, limit?: number): AnyNode[];
+//# sourceMappingURL=legacy.d.ts.map