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/framer-motion/dist/es/utils/reduced-motion/use-reduced-motion.mjs

@@ -0,0 +1,47 @@
+import { useState } from 'react';
+import { initPrefersReducedMotion } from './index.mjs';
+import { warnOnce } from '../warn-once.mjs';
+import { hasReducedMotionListener, prefersReducedMotion } from './state.mjs';
+
+/**
+ * A hook that returns `true` if we should be using reduced motion based on the current device's Reduced Motion setting.
+ *
+ * This can be used to implement changes to your UI based on Reduced Motion. For instance, replacing motion-sickness inducing
+ * `x`/`y` animations with `opacity`, disabling the autoplay of background videos, or turning off parallax motion.
+ *
+ * It will actively respond to changes and re-render your components with the latest setting.
+ *
+ * ```jsx
+ * export function Sidebar({ isOpen }) {
+ *   const shouldReduceMotion = useReducedMotion()
+ *   const closedX = shouldReduceMotion ? 0 : "-100%"
+ *
+ *   return (
+ *     <motion.div animate={{
+ *       opacity: isOpen ? 1 : 0,
+ *       x: isOpen ? 0 : closedX
+ *     }} />
+ *   )
+ * }
+ * ```
+ *
+ * @return boolean
+ *
+ * @public
+ */
+function useReducedMotion() {
+    /**
+     * Lazy initialisation of prefersReducedMotion
+     */
+    !hasReducedMotionListener.current && initPrefersReducedMotion();
+    const [shouldReduceMotion] = useState(prefersReducedMotion.current);
+    if (process.env.NODE_ENV !== "production") {
+        warnOnce(shouldReduceMotion !== true, "You have Reduced Motion enabled on your device. Animations may not appear as expected.");
+    }
+    /**
+     * TODO See if people miss automatically updating shouldReduceMotion setting
+     */
+    return shouldReduceMotion;
+}
+
+export { useReducedMotion };