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/lodash/seq.js

@@ -0,0 +1,16 @@
+module.exports = {
+  'at': require('./wrapperAt'),
+  'chain': require('./chain'),
+  'commit': require('./commit'),
+  'lodash': require('./wrapperLodash'),
+  'next': require('./next'),
+  'plant': require('./plant'),
+  'reverse': require('./wrapperReverse'),
+  'tap': require('./tap'),
+  'thru': require('./thru'),
+  'toIterator': require('./toIterator'),
+  'toJSON': require('./toJSON'),
+  'value': require('./wrapperValue'),
+  'valueOf': require('./valueOf'),
+  'wrapperChain': require('./wrapperChain')
+};