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/core-js/es/function/bind.js

@@ -0,0 +1,5 @@
+'use strict';
+require('../../modules/es.function.bind');
+var entryUnbind = require('../../internals/entry-unbind');
+
+module.exports = entryUnbind('Function', 'bind');

node_modules/core-js/es/function/has-instance.js

@@ -0,0 +1,5 @@
+'use strict';
+require('../../modules/es.function.has-instance');
+var wellKnownSymbol = require('../../internals/well-known-symbol');
+
+module.exports = Function[wellKnownSymbol('hasInstance')];

node_modules/core-js/es/function/index.js

@@ -0,0 +1,7 @@
+'use strict';
+require('../../modules/es.function.bind');
+require('../../modules/es.function.name');
+require('../../modules/es.function.has-instance');
+var path = require('../../internals/path');
+
+module.exports = path.Function;

node_modules/core-js/es/function/name.js

@@ -0,0 +1,2 @@
+'use strict';
+require('../../modules/es.function.name');

node_modules/core-js/es/function/virtual/bind.js

@@ -0,0 +1,5 @@
+'use strict';
+require('../../../modules/es.function.bind');
+var getBuiltInPrototypeMethod = require('../../../internals/get-built-in-prototype-method');
+
+module.exports = getBuiltInPrototypeMethod('Function', 'bind');

node_modules/core-js/es/function/virtual/index.js

@@ -0,0 +1,5 @@
+'use strict';
+require('../../../modules/es.function.bind');
+var entryVirtual = require('../../../internals/entry-virtual');
+
+module.exports = entryVirtual('Function');