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-module-utils/contextCompat.d.ts

@@ -0,0 +1,38 @@
+import { Scope, SourceCode, Rule } from 'eslint';
+import * as ESTree from 'estree';
+
+type LegacyContext = {
+  getFilename: () => string,
+  getPhysicalFilename: () => string,
+  getSourceCode: () => SourceCode,
+  getScope: never,
+  getAncestors: never,
+  getDeclaredVariables: never,
+};
+
+type NewContext = {
+  filename: string,
+  sourceCode: SourceCode,
+  getPhysicalFilename?: () => string,
+  getScope: () => Scope.Scope,
+  getAncestors: () => ESTree.Node[],
+  getDeclaredVariables: (node: ESTree.Node) => Scope.Variable[],
+};
+
+export type Context = LegacyContext | NewContext | Rule.RuleContext;
+
+declare function getAncestors(context: Context, node: ESTree.Node): ESTree.Node[];
+declare function getDeclaredVariables(context: Context, node: ESTree.Node): Scope.Variable[];
+declare function getFilename(context: Context): string;
+declare function getPhysicalFilename(context: Context): string;
+declare function getScope(context: Context, node: ESTree.Node): Scope.Scope;
+declare function getSourceCode(context: Context): SourceCode;
+
+export {
+  getAncestors,
+  getDeclaredVariables,
+  getFilename,
+  getPhysicalFilename,
+  getScope,
+  getSourceCode,
+};