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/animation/interfaces/single-value.mjs

@@ -0,0 +1,11 @@
+import { animateMotionValue } from './motion-value.mjs';
+import { motionValue } from '../../value/index.mjs';
+import { isMotionValue } from '../../value/utils/is-motion-value.mjs';
+
+function animateSingleValue(value, keyframes, options) {
+    const motionValue$1 = isMotionValue(value) ? value : motionValue(value);
+    motionValue$1.start(animateMotionValue("", motionValue$1, keyframes, options));
+    return motionValue$1.animation;
+}
+
+export { animateSingleValue };