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/projection/node/state.mjs

@@ -0,0 +1,19 @@
+/**
+ * This should only ever be modified on the client otherwise it'll
+ * persist through server requests. If we need instanced states we
+ * could lazy-init via root.
+ */
+const globalProjectionState = {
+    /**
+     * Global flag as to whether the tree has animated since the last time
+     * we resized the window
+     */
+    hasAnimatedSinceResize: true,
+    /**
+     * We set this to true once, on the first update. Any nodes added to the tree beyond that
+     * update will be given a `data-projection-id` attribute.
+     */
+    hasEverUpdated: false,
+};
+
+export { globalProjectionState };