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/rxjs/dist/esm/internal/util/isReadableStreamLike.js

@@ -0,0 +1,23 @@
+import { __asyncGenerator, __await } from "tslib";
+import { isFunction } from './isFunction';
+export function readableStreamLikeToAsyncGenerator(readableStream) {
+    return __asyncGenerator(this, arguments, function* readableStreamLikeToAsyncGenerator_1() {
+        const reader = readableStream.getReader();
+        try {
+            while (true) {
+                const { value, done } = yield __await(reader.read());
+                if (done) {
+                    return yield __await(void 0);
+                }
+                yield yield __await(value);
+            }
+        }
+        finally {
+            reader.releaseLock();
+        }
+    });
+}
+export function isReadableStreamLike(obj) {
+    return isFunction(obj === null || obj === void 0 ? void 0 : obj.getReader);
+}
+//# sourceMappingURL=isReadableStreamLike.js.map