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/webpack-dev-server/client/utils/stripAnsi.js

@@ -0,0 +1,18 @@
+var ansiRegex = new RegExp(["[\\u001B\\u009B][[\\]()#;?]*(?:(?:(?:(?:;[-a-zA-Z\\d\\/#&.:=?%@~_]+)*|[a-zA-Z\\d]+(?:;[-a-zA-Z\\d\\/#&.:=?%@~_]*)*)?\\u0007)", "(?:(?:\\d{1,4}(?:;\\d{0,4})*)?[\\dA-PR-TZcf-nq-uy=><~]))"].join("|"), "g");
+
+/**
+ *
+ * Strip [ANSI escape codes](https://en.wikipedia.org/wiki/ANSI_escape_code) from a string.
+ * Adapted from code originally released by Sindre Sorhus
+ * Licensed the MIT License
+ *
+ * @param {string} string
+ * @return {string}
+ */
+function stripAnsi(string) {
+  if (typeof string !== "string") {
+    throw new TypeError("Expected a `string`, got `".concat(typeof string, "`"));
+  }
+  return string.replace(ansiRegex, "");
+}
+export default stripAnsi;