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/moment-timezone/moment-timezone-utils.d.ts

@@ -0,0 +1,70 @@
+import moment = require('moment');
+import { MomentTimezone } from "./index";
+
+declare module 'moment' {
+
+    /** Parsed / unpacked zone data. */
+    interface UnpackedZone {
+        /** The uniquely identifying name of the time zone. */
+        name: string;
+        /** zone abbreviations */
+        abbrs: Array<string>;
+        /** (measured in milliseconds) */
+        untils: Array<number | null>;
+        /** (measured in minutes) */
+        offsets: Array<number>;
+    }
+
+    /** Bundle of zone data and links for multiple timezones */
+    interface PackedZoneBundle {
+        version: string;
+        zones: Array<string>;
+        links: Array<string>;
+    }
+
+    /** Bundle of zone data and links for multiple timezones */
+    interface UnpackedZoneBundle {
+        version: string;
+        zones: Array<UnpackedZone>;
+        links: Array<string>;
+    }
+    
+    /** extends MomentTimezone declared in index */
+    interface MomentTimezone {
+        /** Converts zone data in the unpacked format to the packed format. */
+        pack(unpackedObject: UnpackedZone): string;
+
+        /** Convert a base 10 number to a base 60 string. */
+        packBase60(input: number, precision?: number): string;
+
+        /** Create links out of two zones that share data.
+         * @returns A new ZoneBundle with duplicate zone data replaced by links
+         */
+        createLinks(unlinked: UnpackedZoneBundle): PackedZoneBundle;
+
+        /**
+         * Filter out data for years outside a certain range.
+         * @return a new, filtered UnPackedZone object
+         */
+        filterYears(unpackedZone: UnpackedZone, startYear: number, endYear: number): UnpackedZone;
+        /**
+         * Filter out data for years outside a certain range.
+         * @return a new, filtered UnPackedZone object
+         */
+        filterYears(unpackedZone: UnpackedZone, startAndEndYear: number): UnpackedZone;
+
+        /**
+         * Combines packing, link creation, and subsetting of years into one simple interface.
+         * Pass in an unpacked bundle, start year, and end year and get a filtered, linked, packed bundle back.
+         */
+        filterLinkPack(unpackedBundle: UnpackedZoneBundle, startYear: number, endYear: number): PackedZoneBundle;
+        /**
+         * Combines packing, link creation, and subsetting of years into one simple interface.
+         * Pass in an unpacked bundle, start year, and end year and get a filtered, linked, packed bundle back.
+         */
+        filterLinkPack(unpackedBundle: UnpackedZoneBundle, startAndEndYear: number): PackedZoneBundle;
+    }
+}
+
+// require("moment-timezone") === require("moment")
+export = moment;