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/csso/cjs/restructure/index.cjs

@@ -0,0 +1,39 @@
+'use strict';
+
+const index = require('./prepare/index.cjs');
+const _1MergeAtrule = require('./1-mergeAtrule.cjs');
+const _2InitialMergeRuleset = require('./2-initialMergeRuleset.cjs');
+const _3DisjoinRuleset = require('./3-disjoinRuleset.cjs');
+const _4RestructShorthand = require('./4-restructShorthand.cjs');
+const _6RestructBlock = require('./6-restructBlock.cjs');
+const _7MergeRuleset = require('./7-mergeRuleset.cjs');
+const _8RestructRuleset = require('./8-restructRuleset.cjs');
+
+function restructure(ast, options) {
+    // prepare ast for restructing
+    const indexer = index(ast, options);
+    options.logger('prepare', ast);
+
+    _1MergeAtrule(ast, options);
+    options.logger('mergeAtrule', ast);
+
+    _2InitialMergeRuleset(ast);
+    options.logger('initialMergeRuleset', ast);
+
+    _3DisjoinRuleset(ast);
+    options.logger('disjoinRuleset', ast);
+
+    _4RestructShorthand(ast, indexer);
+    options.logger('restructShorthand', ast);
+
+    _6RestructBlock(ast);
+    options.logger('restructBlock', ast);
+
+    _7MergeRuleset(ast);
+    options.logger('mergeRuleset', ast);
+
+    _8RestructRuleset(ast);
+    options.logger('restructRuleset', ast);
+}
+
+module.exports = restructure;