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/selector-no-vendor-prefix/index.js

@@ -0,0 +1,84 @@
+'use strict';
+
+const isAutoprefixable = require('../../utils/isAutoprefixable');
+const isStandardSyntaxRule = require('../../utils/isStandardSyntaxRule');
+const optionsMatches = require('../../utils/optionsMatches');
+const parseSelector = require('../../utils/parseSelector');
+const report = require('../../utils/report');
+const ruleMessages = require('../../utils/ruleMessages');
+const validateOptions = require('../../utils/validateOptions');
+const { isString, isRegExp } = require('../../utils/validateTypes');
+
+const ruleName = 'selector-no-vendor-prefix';
+
+const messages = ruleMessages(ruleName, {
+	rejected: (selector) => `Unexpected vendor-prefix "${selector}"`,
+});
+
+const meta = {
+	url: 'https://stylelint.io/user-guide/rules/selector-no-vendor-prefix',
+	fixable: true,
+};
+
+/** @type {import('stylelint').Rule} */
+const rule = (primary, secondaryOptions, context) => {
+	return (root, result) => {
+		const validOptions = validateOptions(
+			result,
+			ruleName,
+			{ actual: primary },
+			{
+				actual: secondaryOptions,
+				possible: {
+					ignoreSelectors: [isString, isRegExp],
+				},
+				optional: true,
+			},
+		);
+
+		if (!validOptions) {
+			return;
+		}
+
+		root.walkRules((ruleNode) => {
+			if (!isStandardSyntaxRule(ruleNode)) {
+				return;
+			}
+
+			const selector = ruleNode.selector;
+
+			parseSelector(selector, result, ruleNode, (selectorTree) => {
+				selectorTree.walkPseudos((pseudoNode) => {
+					const { value } = pseudoNode;
+
+					if (!isAutoprefixable.selector(value)) {
+						return;
+					}
+
+					if (optionsMatches(secondaryOptions, 'ignoreSelectors', value)) {
+						return;
+					}
+
+					if (context.fix) {
+						ruleNode.selector = isAutoprefixable.unprefix(selector);
+
+						return;
+					}
+
+					report({
+						result,
+						ruleName,
+						message: messages.rejected(value),
+						node: ruleNode,
+						word: value,
+					});
+				});
+			});
+		});
+	};
+};
+
+rule.ruleName = ruleName;
+rule.messages = messages;
+rule.meta = meta;
+module.exports = rule;