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/value/use-combine-values.mjs

@@ -0,0 +1,37 @@
+import { useMotionValue } from './use-motion-value.mjs';
+import { useIsomorphicLayoutEffect } from '../utils/use-isomorphic-effect.mjs';
+import { cancelFrame, frame } from '../frameloop/frame.mjs';
+
+function useCombineMotionValues(values, combineValues) {
+    /**
+     * Initialise the returned motion value. This remains the same between renders.
+     */
+    const value = useMotionValue(combineValues());
+    /**
+     * Create a function that will update the template motion value with the latest values.
+     * This is pre-bound so whenever a motion value updates it can schedule its
+     * execution in Framesync. If it's already been scheduled it won't be fired twice
+     * in a single frame.
+     */
+    const updateValue = () => value.set(combineValues());
+    /**
+     * Synchronously update the motion value with the latest values during the render.
+     * This ensures that within a React render, the styles applied to the DOM are up-to-date.
+     */
+    updateValue();
+    /**
+     * Subscribe to all motion values found within the template. Whenever any of them change,
+     * schedule an update.
+     */
+    useIsomorphicLayoutEffect(() => {
+        const scheduleUpdate = () => frame.update(updateValue, false, true);
+        const subscriptions = values.map((v) => v.on("change", scheduleUpdate));
+        return () => {
+            subscriptions.forEach((unsubscribe) => unsubscribe());
+            cancelFrame(updateValue);
+        };
+    });
+    return value;
+}
+
+export { useCombineMotionValues };