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/lodash/zipObjectDeep.js

@@ -0,0 +1,23 @@
+var baseSet = require('./_baseSet'),
+    baseZipObject = require('./_baseZipObject');
+
+/**
+ * This method is like `_.zipObject` except that it supports property paths.
+ *
+ * @static
+ * @memberOf _
+ * @since 4.1.0
+ * @category Array
+ * @param {Array} [props=[]] The property identifiers.
+ * @param {Array} [values=[]] The property values.
+ * @returns {Object} Returns the new object.
+ * @example
+ *
+ * _.zipObjectDeep(['a.b[0].c', 'a.b[1].d'], [1, 2]);
+ * // => { 'a': { 'b': [{ 'c': 1 }, { 'd': 2 }] } }
+ */
+function zipObjectDeep(props, values) {
+  return baseZipObject(props || [], values || [], baseSet);
+}
+
+module.exports = zipObjectDeep;