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/@wordpress/compose/build-module/hooks/use-previous/index.js

@@ -0,0 +1,25 @@
+/**
+ * WordPress dependencies
+ */
+import { useEffect, useRef } from '@wordpress/element';
+
+/**
+ * Use something's value from the previous render.
+ * Based on https://usehooks.com/usePrevious/.
+ *
+ * @param value The value to track.
+ *
+ * @return The value from the previous render.
+ */
+export default function usePrevious(value) {
+  const ref = useRef();
+
+  // Store current value in ref.
+  useEffect(() => {
+    ref.current = value;
+  }, [value]); // Re-run when value changes.
+
+  // Return previous value (happens before update in useEffect above).
+  return ref.current;
+}
+//# sourceMappingURL=index.js.map

node_modules/@wordpress/compose/build-module/hooks/use-previous/index.js.map

@@ -0,0 +1 @@
+{"version":3,"names":["useEffect","useRef","usePrevious","value","ref","current"],"sources":["@wordpress/compose/src/hooks/use-previous/index.ts"],"sourcesContent":["/**\n * WordPress dependencies\n */\nimport { useEffect, useRef } from '@wordpress/element';\n\n/**\n * Use something's value from the previous render.\n * Based on https://usehooks.com/usePrevious/.\n *\n * @param value The value to track.\n *\n * @return The value from the previous render.\n */\nexport default function usePrevious< T >( value: T ): T | undefined {\n\tconst ref = useRef< T >();\n\n\t// Store current value in ref.\n\tuseEffect( () => {\n\t\tref.current = value;\n\t}, [ value ] ); // Re-run when value changes.\n\n\t// Return previous value (happens before update in useEffect above).\n\treturn ref.current;\n}\n"],"mappings":"AAAA;AACA;AACA;AACA,SAASA,SAAS,EAAEC,MAAM,QAAQ,oBAAoB;;AAEtD;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA,eAAe,SAASC,WAAWA,CAAOC,KAAQ,EAAkB;EACnE,MAAMC,GAAG,GAAGH,MAAM,CAAM,CAAC;;EAEzB;EACAD,SAAS,CAAE,MAAM;IAChBI,GAAG,CAACC,OAAO,GAAGF,KAAK;EACpB,CAAC,EAAE,CAAEA,KAAK,CAAG,CAAC,CAAC,CAAC;;EAEhB;EACA,OAAOC,GAAG,CAACC,OAAO;AACnB","ignoreList":[]}