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/date-fns/esm/getDefaultOptions/index.d.ts

@@ -0,0 +1,4 @@
+// This file is generated automatically by `scripts/build/typings.js`. Please, don't change it.
+
+import { getDefaultOptions } from 'date-fns'
+export default getDefaultOptions

node_modules/date-fns/esm/getDefaultOptions/index.js

@@ -0,0 +1,29 @@
+import { getDefaultOptions as getInternalDefaultOptions } from "../_lib/defaultOptions/index.js";
+import assign from "../_lib/assign/index.js";
+/**
+ * @name getDefaultOptions
+ * @category Common Helpers
+ * @summary Get default options.
+ * @pure false
+ *
+ * @description
+ * Returns an object that contains defaults for
+ * `options.locale`, `options.weekStartsOn` and `options.firstWeekContainsDate`
+ * arguments for all functions.
+ *
+ * You can change these with [setDefaultOptions]{@link https://date-fns.org/docs/setDefaultOptions}.
+ *
+ * @returns {Object} default options
+ *
+ * @example
+ * const result = getDefaultOptions()
+ * //=> {}
+ *
+ * @example
+ * setDefaultOptions({ weekStarsOn: 1, firstWeekContainsDate: 4 })
+ * const result = getDefaultOptions()
+ * //=> { weekStarsOn: 1, firstWeekContainsDate: 4 }
+ */
+export default function getDefaultOptions() {
+  return assign({}, getInternalDefaultOptions());
+}

node_modules/date-fns/esm/getDefaultOptions/index.js.flow

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+// @flow
+// This file is generated automatically by `scripts/build/typings.js`. Please, don't change it.
+
+export type Interval = {
+  start: Date | number,
+  end: Date | number,
+}
+
+export type Locale = {
+  code?: string,
+  formatDistance?: (...args: Array<any>) => any,
+  formatRelative?: (...args: Array<any>) => any,
+  localize?: {
+    ordinalNumber: (...args: Array<any>) => any,
+    era: (...args: Array<any>) => any,
+    quarter: (...args: Array<any>) => any,
+    month: (...args: Array<any>) => any,
+    day: (...args: Array<any>) => any,
+    dayPeriod: (...args: Array<any>) => any,
+  },
+  formatLong?: {
+    date: (...args: Array<any>) => any,
+    time: (...args: Array<any>) => any,
+    dateTime: (...args: Array<any>) => any,
+  },
+  match?: {
+    ordinalNumber: (...args: Array<any>) => any,
+    era: (...args: Array<any>) => any,
+    quarter: (...args: Array<any>) => any,
+    month: (...args: Array<any>) => any,
+    day: (...args: Array<any>) => any,
+    dayPeriod: (...args: Array<any>) => any,
+  },
+  options?: {
+    weekStartsOn?: 0 | 1 | 2 | 3 | 4 | 5 | 6,
+    firstWeekContainsDate?: 1 | 2 | 3 | 4 | 5 | 6 | 7,
+  },
+}
+
+export type Duration = {
+  years?: number,
+  months?: number,
+  weeks?: number,
+  days?: number,
+  hours?: number,
+  minutes?: number,
+  seconds?: number,
+}
+
+export type Day = 0 | 1 | 2 | 3 | 4 | 5 | 6
+
+declare module.exports: () => Object

node_modules/date-fns/esm/getDefaultOptions/package.json

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+{
+  "sideEffects": false,
+  "typings": "../../typings.d.ts"
+}