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/components/build-module/tools-panel/tools-panel-item/component.js

@@ -0,0 +1,34 @@
+import { createElement } from "react";
+/**
+ * External dependencies
+ */
+
+/**
+ * Internal dependencies
+ */
+import { useToolsPanelItem } from './hook';
+import { View } from '../../view';
+import { contextConnect } from '../../context';
+// This wraps controls to be conditionally displayed within a tools panel. It
+// prevents props being applied to HTML elements that would make them invalid.
+const UnconnectedToolsPanelItem = (props, forwardedRef) => {
+  const {
+    children,
+    isShown,
+    shouldRenderPlaceholder,
+    ...toolsPanelItemProps
+  } = useToolsPanelItem(props);
+  if (!isShown) {
+    return shouldRenderPlaceholder ? createElement(View, {
+      ...toolsPanelItemProps,
+      ref: forwardedRef
+    }) : null;
+  }
+  return createElement(View, {
+    ...toolsPanelItemProps,
+    ref: forwardedRef
+  }, children);
+};
+export const ToolsPanelItem = contextConnect(UnconnectedToolsPanelItem, 'ToolsPanelItem');
+export default ToolsPanelItem;
+//# sourceMappingURL=component.js.map

node_modules/@wordpress/components/build-module/tools-panel/tools-panel-item/component.js.map

@@ -0,0 +1 @@
+{"version":3,"names":["useToolsPanelItem","View","contextConnect","UnconnectedToolsPanelItem","props","forwardedRef","children","isShown","shouldRenderPlaceholder","toolsPanelItemProps","createElement","ref","ToolsPanelItem"],"sources":["@wordpress/components/src/tools-panel/tools-panel-item/component.tsx"],"sourcesContent":["/**\n * External dependencies\n */\nimport type { ForwardedRef } from 'react';\n\n/**\n * Internal dependencies\n */\nimport { useToolsPanelItem } from './hook';\nimport { View } from '../../view';\nimport type { WordPressComponentProps } from '../../context';\nimport { contextConnect } from '../../context';\nimport type { ToolsPanelItemProps } from '../types';\n\n// This wraps controls to be conditionally displayed within a tools panel. It\n// prevents props being applied to HTML elements that would make them invalid.\nconst UnconnectedToolsPanelItem = (\n\tprops: WordPressComponentProps< ToolsPanelItemProps, 'div' >,\n\tforwardedRef: ForwardedRef< any >\n) => {\n\tconst {\n\t\tchildren,\n\t\tisShown,\n\t\tshouldRenderPlaceholder,\n\t\t...toolsPanelItemProps\n\t} = useToolsPanelItem( props );\n\n\tif ( ! isShown ) {\n\t\treturn shouldRenderPlaceholder ? (\n\t\t\t<View { ...toolsPanelItemProps } ref={ forwardedRef } />\n\t\t) : null;\n\t}\n\n\treturn (\n\t\t<View { ...toolsPanelItemProps } ref={ forwardedRef }>\n\t\t\t{ children }\n\t\t</View>\n\t);\n};\n\nexport const ToolsPanelItem = contextConnect(\n\tUnconnectedToolsPanelItem,\n\t'ToolsPanelItem'\n);\n\nexport default ToolsPanelItem;\n"],"mappings":";AAAA;AACA;AACA;;AAGA;AACA;AACA;AACA,SAASA,iBAAiB,QAAQ,QAAQ;AAC1C,SAASC,IAAI,QAAQ,YAAY;AAEjC,SAASC,cAAc,QAAQ,eAAe;AAG9C;AACA;AACA,MAAMC,yBAAyB,GAAGA,CACjCC,KAA4D,EAC5DC,YAAiC,KAC7B;EACJ,MAAM;IACLC,QAAQ;IACRC,OAAO;IACPC,uBAAuB;IACvB,GAAGC;EACJ,CAAC,GAAGT,iBAAiB,CAAEI,KAAM,CAAC;EAE9B,IAAK,CAAEG,OAAO,EAAG;IAChB,OAAOC,uBAAuB,GAC7BE,aAAA,CAACT,IAAI;MAAA,GAAMQ,mBAAmB;MAAGE,GAAG,EAAGN;IAAc,CAAE,CAAC,GACrD,IAAI;EACT;EAEA,OACCK,aAAA,CAACT,IAAI;IAAA,GAAMQ,mBAAmB;IAAGE,GAAG,EAAGN;EAAc,GAClDC,QACG,CAAC;AAET,CAAC;AAED,OAAO,MAAMM,cAAc,GAAGV,cAAc,CAC3CC,yBAAyB,EACzB,gBACD,CAAC;AAED,eAAeS,cAAc"}

node_modules/@wordpress/components/build-module/tools-panel/tools-panel-item/hook.js

@@ -0,0 +1,139 @@
+/**
+ * WordPress dependencies
+ */
+import { usePrevious } from '@wordpress/compose';
+import { useCallback, useEffect, useLayoutEffect, useMemo } from '@wordpress/element';
+
+/**
+ * Internal dependencies
+ */
+import * as styles from '../styles';
+import { useToolsPanelContext } from '../context';
+import { useContextSystem } from '../../context';
+import { useCx } from '../../utils/hooks/use-cx';
+const noop = () => {};
+export function useToolsPanelItem(props) {
+  const {
+    className,
+    hasValue,
+    isShownByDefault = false,
+    label,
+    panelId,
+    resetAllFilter = noop,
+    onDeselect,
+    onSelect,
+    ...otherProps
+  } = useContextSystem(props, 'ToolsPanelItem');
+  const {
+    panelId: currentPanelId,
+    menuItems,
+    registerResetAllFilter,
+    deregisterResetAllFilter,
+    registerPanelItem,
+    deregisterPanelItem,
+    flagItemCustomization,
+    isResetting,
+    shouldRenderPlaceholderItems: shouldRenderPlaceholder,
+    firstDisplayedItem,
+    lastDisplayedItem,
+    __experimentalFirstVisibleItemClass,
+    __experimentalLastVisibleItemClass
+  } = useToolsPanelContext();
+
+  // hasValue is a new function on every render, so do not add it as a
+  // dependency to the useCallback hook! If needed, we should use a ref.
+  // eslint-disable-next-line react-hooks/exhaustive-deps
+  const hasValueCallback = useCallback(hasValue, [panelId]);
+  // resetAllFilter is a new function on every render, so do not add it as a
+  // dependency to the useCallback hook! If needed, we should use a ref.
+  // eslint-disable-next-line react-hooks/exhaustive-deps
+  const resetAllFilterCallback = useCallback(resetAllFilter, [panelId]);
+  const previousPanelId = usePrevious(currentPanelId);
+  const hasMatchingPanel = currentPanelId === panelId || currentPanelId === null;
+
+  // Registering the panel item allows the panel to include it in its
+  // automatically generated menu and determine its initial checked status.
+  //
+  // This is performed in a layout effect to ensure that the panel item
+  // is registered before it is rendered preventing a rendering glitch.
+  // See: https://github.com/WordPress/gutenberg/issues/56470
+  useLayoutEffect(() => {
+    if (hasMatchingPanel && previousPanelId !== null) {
+      registerPanelItem({
+        hasValue: hasValueCallback,
+        isShownByDefault,
+        label,
+        panelId
+      });
+    }
+    return () => {
+      if (previousPanelId === null && !!currentPanelId || currentPanelId === panelId) {
+        deregisterPanelItem(label);
+      }
+    };
+  }, [currentPanelId, hasMatchingPanel, isShownByDefault, label, hasValueCallback, panelId, previousPanelId, registerPanelItem, deregisterPanelItem]);
+  useEffect(() => {
+    if (hasMatchingPanel) {
+      registerResetAllFilter(resetAllFilterCallback);
+    }
+    return () => {
+      if (hasMatchingPanel) {
+        deregisterResetAllFilter(resetAllFilterCallback);
+      }
+    };
+  }, [registerResetAllFilter, deregisterResetAllFilter, resetAllFilterCallback, hasMatchingPanel]);
+
+  // Note: `label` is used as a key when building menu item state in
+  // `ToolsPanel`.
+  const menuGroup = isShownByDefault ? 'default' : 'optional';
+  const isMenuItemChecked = menuItems?.[menuGroup]?.[label];
+  const wasMenuItemChecked = usePrevious(isMenuItemChecked);
+  const isRegistered = menuItems?.[menuGroup]?.[label] !== undefined;
+  const isValueSet = hasValue();
+  const wasValueSet = usePrevious(isValueSet);
+  const newValueSet = isValueSet && !wasValueSet;
+
+  // Notify the panel when an item's value has been set.
+  useEffect(() => {
+    if (!newValueSet) {
+      return;
+    }
+    flagItemCustomization(label, menuGroup);
+  }, [newValueSet, menuGroup, label, flagItemCustomization]);
+
+  // Determine if the panel item's corresponding menu is being toggled and
+  // trigger appropriate callback if it is.
+  useEffect(() => {
+    // We check whether this item is currently registered as items rendered
+    // via fills can persist through the parent panel being remounted.
+    // See: https://github.com/WordPress/gutenberg/pull/45673
+    if (!isRegistered || isResetting || !hasMatchingPanel) {
+      return;
+    }
+    if (isMenuItemChecked && !isValueSet && !wasMenuItemChecked) {
+      onSelect?.();
+    }
+    if (!isMenuItemChecked && wasMenuItemChecked) {
+      onDeselect?.();
+    }
+  }, [hasMatchingPanel, isMenuItemChecked, isRegistered, isResetting, isValueSet, wasMenuItemChecked, onSelect, onDeselect]);
+
+  // The item is shown if it is a default control regardless of whether it
+  // has a value. Optional items are shown when they are checked or have
+  // a value.
+  const isShown = isShownByDefault ? menuItems?.[menuGroup]?.[label] !== undefined : isMenuItemChecked;
+  const cx = useCx();
+  const classes = useMemo(() => {
+    const shouldApplyPlaceholderStyles = shouldRenderPlaceholder && !isShown;
+    const firstItemStyle = firstDisplayedItem === label && __experimentalFirstVisibleItemClass;
+    const lastItemStyle = lastDisplayedItem === label && __experimentalLastVisibleItemClass;
+    return cx(styles.ToolsPanelItem, shouldApplyPlaceholderStyles && styles.ToolsPanelItemPlaceholder, !shouldApplyPlaceholderStyles && className, firstItemStyle, lastItemStyle);
+  }, [isShown, shouldRenderPlaceholder, className, cx, firstDisplayedItem, lastDisplayedItem, __experimentalFirstVisibleItemClass, __experimentalLastVisibleItemClass, label]);
+  return {
+    ...otherProps,
+    isShown,
+    shouldRenderPlaceholder,
+    className: classes
+  };
+}
+//# sourceMappingURL=hook.js.map

node_modules/@wordpress/components/build-module/tools-panel/tools-panel-item/index.js

@@ -0,0 +1,3 @@
+export { default } from './component';
+export { useToolsPanelItem } from './hook';
+//# sourceMappingURL=index.js.map

node_modules/@wordpress/components/build-module/tools-panel/tools-panel-item/index.js.map

@@ -0,0 +1 @@
+{"version":3,"names":["default","useToolsPanelItem"],"sources":["@wordpress/components/src/tools-panel/tools-panel-item/index.ts"],"sourcesContent":["export { default } from './component';\nexport { useToolsPanelItem } from './hook';\n"],"mappings":"AAAA,SAASA,OAAO,QAAQ,aAAa;AACrC,SAASC,iBAAiB,QAAQ,QAAQ"}