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/ajv-keywords/keywords/index.js

@@ -0,0 +1,22 @@
+'use strict';
+
+module.exports = {
+  'instanceof': require('./instanceof'),
+  range: require('./range'),
+  regexp: require('./regexp'),
+  'typeof': require('./typeof'),
+  dynamicDefaults: require('./dynamicDefaults'),
+  allRequired: require('./allRequired'),
+  anyRequired: require('./anyRequired'),
+  oneRequired: require('./oneRequired'),
+  prohibited: require('./prohibited'),
+  uniqueItemProperties: require('./uniqueItemProperties'),
+  deepProperties: require('./deepProperties'),
+  deepRequired: require('./deepRequired'),
+  formatMinimum: require('./formatMinimum'),
+  formatMaximum: require('./formatMaximum'),
+  patternRequired: require('./patternRequired'),
+  'switch': require('./switch'),
+  select: require('./select'),
+  transform: require('./transform')
+};