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/node-addon-api/package-support.json

@@ -0,0 +1,21 @@
+{
+  "versions": [
+    {
+      "version": "*",
+      "target": {
+        "node": "active"
+      },
+      "response": {
+        "type": "time-permitting",
+        "paid": false,
+        "contact": {
+          "name": "node-addon-api team",
+          "url": "https://github.com/nodejs/node-addon-api/issues"
+        }
+      },
+      "backing": [ { "project": "https://github.com/nodejs" },
+                   { "foundation": "https://openjsf.org/" }
+      ]
+    }
+  ]
+}