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/synckit/lib/common.js

@@ -0,0 +1,22 @@
+const NODE_OPTIONS = process.env.NODE_OPTIONS?.split(/\s+/);
+export const hasFlag = (flag) => NODE_OPTIONS?.includes(flag) || process.argv.includes(flag);
+export const parseVersion = (version) => version.split('.').map(Number.parseFloat);
+export const compareVersion = (version1, version2) => {
+    const versions1 = parseVersion(version1);
+    const versions2 = parseVersion(version2);
+    const length = Math.max(versions1.length, versions2.length);
+    for (let i = 0; i < length; i++) {
+        const v1 = versions1[i] || 0;
+        const v2 = versions2[i] || 0;
+        if (v1 > v2) {
+            return 1;
+        }
+        if (v1 < v2) {
+            return -1;
+        }
+    }
+    return 0;
+};
+export const NODE_VERSION = process.versions.node;
+export const compareNodeVersion = (version) => compareVersion(NODE_VERSION, version);
+//# sourceMappingURL=common.js.map