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/declaration-property-value-allowed-list/index.js

@@ -0,0 +1,69 @@
+'use strict';
+
+const declarationValueIndex = require('../../utils/declarationValueIndex');
+const matchesStringOrRegExp = require('../../utils/matchesStringOrRegExp');
+const optionsMatches = require('../../utils/optionsMatches');
+const report = require('../../utils/report');
+const ruleMessages = require('../../utils/ruleMessages');
+const validateObjectWithArrayProps = require('../../utils/validateObjectWithArrayProps');
+const validateOptions = require('../../utils/validateOptions');
+const { isString, isRegExp } = require('../../utils/validateTypes');
+const vendor = require('../../utils/vendor');
+
+const ruleName = 'declaration-property-value-allowed-list';
+
+const messages = ruleMessages(ruleName, {
+	rejected: (property, value) => `Unexpected value "${value}" for property "${property}"`,
+});
+
+const meta = {
+	url: 'https://stylelint.io/user-guide/rules/declaration-property-value-allowed-list',
+};
+
+/** @type {import('stylelint').Rule<Record<string, string | RegExp | Array<string | RegExp>>>} */
+const rule = (primary) => {
+	return (root, result) => {
+		const validOptions = validateOptions(result, ruleName, {
+			actual: primary,
+			possible: [validateObjectWithArrayProps(isString, isRegExp)],
+		});
+
+		if (!validOptions) {
+			return;
+		}
+
+		const propKeys = Object.keys(primary);
+
+		root.walkDecls((decl) => {
+			const { prop, value } = decl;
+
+			const unprefixedProp = vendor.unprefixed(prop);
+			const propPatterns = propKeys.filter((key) => matchesStringOrRegExp(unprefixedProp, key));
+
+			if (propPatterns.length === 0) {
+				return;
+			}
+
+			if (propPatterns.some((pattern) => optionsMatches(primary, pattern, value))) {
+				return;
+			}
+
+			const index = declarationValueIndex(decl);
+			const endIndex = index + decl.value.length;
+
+			report({
+				message: messages.rejected(prop, value),
+				node: decl,
+				index,
+				endIndex,
+				result,
+				ruleName,
+			});
+		});
+	};
+};
+
+rule.ruleName = ruleName;
+rule.messages = messages;
+rule.meta = meta;
+module.exports = rule;