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/_compareAscending.js

@@ -0,0 +1,41 @@
+var isSymbol = require('./isSymbol');
+
+/**
+ * Compares values to sort them in ascending order.
+ *
+ * @private
+ * @param {*} value The value to compare.
+ * @param {*} other The other value to compare.
+ * @returns {number} Returns the sort order indicator for `value`.
+ */
+function compareAscending(value, other) {
+  if (value !== other) {
+    var valIsDefined = value !== undefined,
+        valIsNull = value === null,
+        valIsReflexive = value === value,
+        valIsSymbol = isSymbol(value);
+
+    var othIsDefined = other !== undefined,
+        othIsNull = other === null,
+        othIsReflexive = other === other,
+        othIsSymbol = isSymbol(other);
+
+    if ((!othIsNull && !othIsSymbol && !valIsSymbol && value > other) ||
+        (valIsSymbol && othIsDefined && othIsReflexive && !othIsNull && !othIsSymbol) ||
+        (valIsNull && othIsDefined && othIsReflexive) ||
+        (!valIsDefined && othIsReflexive) ||
+        !valIsReflexive) {
+      return 1;
+    }
+    if ((!valIsNull && !valIsSymbol && !othIsSymbol && value < other) ||
+        (othIsSymbol && valIsDefined && valIsReflexive && !valIsNull && !valIsSymbol) ||
+        (othIsNull && valIsDefined && valIsReflexive) ||
+        (!othIsDefined && valIsReflexive) ||
+        !othIsReflexive) {
+      return -1;
+    }
+  }
+  return 0;
+}
+
+module.exports = compareAscending;