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/addQuarters/index.d.ts

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

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

@@ -0,0 +1,27 @@
+import toInteger from "../_lib/toInteger/index.js";
+import addMonths from "../addMonths/index.js";
+import requiredArgs from "../_lib/requiredArgs/index.js";
+/**
+ * @name addQuarters
+ * @category Quarter Helpers
+ * @summary Add the specified number of year quarters to the given date.
+ *
+ * @description
+ * Add the specified number of year quarters to the given date.
+ *
+ * @param {Date|Number} date - the date to be changed
+ * @param {Number} amount - the amount of quarters to be added. Positive decimals will be rounded using `Math.floor`, decimals less than zero will be rounded using `Math.ceil`.
+ * @returns {Date} the new date with the quarters added
+ * @throws {TypeError} 2 arguments required
+ *
+ * @example
+ * // Add 1 quarter to 1 September 2014:
+ * const result = addQuarters(new Date(2014, 8, 1), 1)
+ * //=> Mon Dec 01 2014 00:00:00
+ */
+export default function addQuarters(dirtyDate, dirtyAmount) {
+  requiredArgs(2, arguments);
+  var amount = toInteger(dirtyAmount);
+  var months = amount * 3;
+  return addMonths(dirtyDate, months);
+}

node_modules/date-fns/esm/addQuarters/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: (date: Date | number, amount: number) => Date

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

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