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/conformsTo.js

@@ -0,0 +1,32 @@
+var baseConformsTo = require('./_baseConformsTo'),
+    keys = require('./keys');
+
+/**
+ * Checks if `object` conforms to `source` by invoking the predicate
+ * properties of `source` with the corresponding property values of `object`.
+ *
+ * **Note:** This method is equivalent to `_.conforms` when `source` is
+ * partially applied.
+ *
+ * @static
+ * @memberOf _
+ * @since 4.14.0
+ * @category Lang
+ * @param {Object} object The object to inspect.
+ * @param {Object} source The object of property predicates to conform to.
+ * @returns {boolean} Returns `true` if `object` conforms, else `false`.
+ * @example
+ *
+ * var object = { 'a': 1, 'b': 2 };
+ *
+ * _.conformsTo(object, { 'b': function(n) { return n > 1; } });
+ * // => true
+ *
+ * _.conformsTo(object, { 'b': function(n) { return n > 2; } });
+ * // => false
+ */
+function conformsTo(object, source) {
+  return source == null || baseConformsTo(object, source, keys(source));
+}
+
+module.exports = conformsTo;