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/date-fns/esm/locale/_lib/buildMatchFn/index.js

@@ -0,0 +1,42 @@
+export default function buildMatchFn(args) {
+  return function (string) {
+    var options = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {};
+    var width = options.width;
+    var matchPattern = width && args.matchPatterns[width] || args.matchPatterns[args.defaultMatchWidth];
+    var matchResult = string.match(matchPattern);
+    if (!matchResult) {
+      return null;
+    }
+    var matchedString = matchResult[0];
+    var parsePatterns = width && args.parsePatterns[width] || args.parsePatterns[args.defaultParseWidth];
+    var key = Array.isArray(parsePatterns) ? findIndex(parsePatterns, function (pattern) {
+      return pattern.test(matchedString);
+    }) : findKey(parsePatterns, function (pattern) {
+      return pattern.test(matchedString);
+    });
+    var value;
+    value = args.valueCallback ? args.valueCallback(key) : key;
+    value = options.valueCallback ? options.valueCallback(value) : value;
+    var rest = string.slice(matchedString.length);
+    return {
+      value: value,
+      rest: rest
+    };
+  };
+}
+function findKey(object, predicate) {
+  for (var key in object) {
+    if (object.hasOwnProperty(key) && predicate(object[key])) {
+      return key;
+    }
+  }
+  return undefined;
+}
+function findIndex(array, predicate) {
+  for (var key = 0; key < array.length; key++) {
+    if (predicate(array[key])) {
+      return key;
+    }
+  }
+  return undefined;
+}