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/stylelint/lib/rules/functionCommaSpaceFix.js

@@ -0,0 +1,49 @@
+'use strict';
+
+/**
+ * @param {{
+ *   div: import('postcss-value-parser').DivNode,
+ *   index: number,
+ *   nodes: import('postcss-value-parser').Node[],
+ *   expectation: string,
+ *   position: 'before' | 'after',
+ *   symb: string,
+ * }} params
+ * @returns {boolean}
+ */
+module.exports = function functionCommaSpaceFix(params) {
+	const { div, index, nodes, expectation, position, symb } = params;
+
+	if (expectation.startsWith('always')) {
+		div[position] = symb;
+
+		return true;
+	}
+
+	if (expectation.startsWith('never')) {
+		div[position] = '';
+
+		for (let i = index + 1; i < nodes.length; i++) {
+			const node = nodes[i];
+
+			if (node === undefined) {
+				continue;
+			}
+
+			if (node.type === 'comment') {
+				continue;
+			}
+
+			if (node.type === 'space') {
+				node.value = '';
+				continue;
+			}
+
+			break;
+		}
+
+		return true;
+	}
+
+	return false;
+};