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/eslint/lib/rules/no-debugger.js

@@ -0,0 +1,43 @@
+/**
+ * @fileoverview Rule to flag use of a debugger statement
+ * @author Nicholas C. Zakas
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+/** @type {import('../shared/types').Rule} */
+module.exports = {
+    meta: {
+        type: "problem",
+
+        docs: {
+            description: "Disallow the use of `debugger`",
+            recommended: true,
+            url: "https://eslint.org/docs/latest/rules/no-debugger"
+        },
+
+        fixable: null,
+        schema: [],
+
+        messages: {
+            unexpected: "Unexpected 'debugger' statement."
+        }
+    },
+
+    create(context) {
+
+        return {
+            DebuggerStatement(node) {
+                context.report({
+                    node,
+                    messageId: "unexpected"
+                });
+            }
+        };
+
+    }
+};