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/mobile/segmented-control/index.native.js

@@ -0,0 +1,146 @@
+import { createElement } from "react";
+/**
+ * External dependencies
+ */
+import { View, TouchableWithoutFeedback, Text, Platform, Animated, Easing } from 'react-native';
+/**
+ * WordPress dependencies
+ */
+import { useState, useEffect } from '@wordpress/element';
+import { usePreferredColorSchemeStyle } from '@wordpress/compose';
+
+/**
+ * Internal dependencies
+ */
+import { performLayoutAnimation } from '../layout-animation';
+import styles from './style.scss';
+const ANIMATION_DURATION = 200;
+const isIOS = Platform.OS === 'ios';
+const Segment = ({
+  isSelected,
+  title,
+  onPress,
+  onLayout,
+  ...props
+}) => {
+  const isSelectedIOS = isIOS && isSelected;
+  const segmentStyle = [styles.segment, isIOS && styles.segmentIOS];
+  const textStyle = usePreferredColorSchemeStyle(styles.buttonTextDefault, styles.buttonTextDefaultDark);
+  const selectedTextStyle = usePreferredColorSchemeStyle(styles.buttonTextSelected, styles.buttonTextSelectedDark);
+  const shadowStyle = usePreferredColorSchemeStyle(styles.shadowIOS, {});
+  return createElement(View, {
+    style: isSelectedIOS && shadowStyle
+  }, createElement(TouchableWithoutFeedback, {
+    onPress: onPress
+  }, createElement(View, {
+    style: segmentStyle,
+    onLayout: onLayout,
+    ...props
+  }, createElement(Text, {
+    style: [textStyle, isSelected && selectedTextStyle],
+    maxFontSizeMultiplier: 2
+  }, title))));
+};
+const SegmentedControls = ({
+  segments,
+  segmentHandler,
+  selectedIndex,
+  addonLeft,
+  addonRight
+}) => {
+  const selectedSegmentIndex = selectedIndex || 0;
+  const [activeSegmentIndex, setActiveSegmentIndex] = useState(selectedSegmentIndex);
+  const [segmentsDimensions, setSegmentsDimensions] = useState({
+    [activeSegmentIndex]: {
+      width: 0,
+      height: 0
+    }
+  });
+  const [positionAnimationValue] = useState(new Animated.Value(0));
+  useEffect(() => {
+    setActiveSegmentIndex(selectedSegmentIndex);
+    segmentHandler(segments[selectedSegmentIndex]);
+    // Disable reason: deferring this refactor to the native team.
+    // see https://github.com/WordPress/gutenberg/pull/41166
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, []);
+  useEffect(() => {
+    positionAnimationValue.setValue(calculateEndValue(activeSegmentIndex));
+    // Disable reason: deferring this refactor to the native team.
+    // see https://github.com/WordPress/gutenberg/pull/41166
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [segmentsDimensions]);
+  const containerStyle = usePreferredColorSchemeStyle(styles.container, styles.containerDark);
+  function performSwatchAnimation(index) {
+    Animated.timing(positionAnimationValue, {
+      toValue: calculateEndValue(index),
+      duration: ANIMATION_DURATION,
+      easing: Easing.ease,
+      useNativeDriver: false
+    }).start();
+  }
+  function calculateEndValue(index) {
+    const {
+      paddingLeft: offset
+    } = isIOS ? styles.containerIOS : styles.container;
+    const widths = Object.values(segmentsDimensions).map(dimension => dimension.width);
+    const widthsDistance = widths.slice(0, index);
+    const widthsDistanceSum = widthsDistance.reduce((sum, n) => sum + n, 0);
+    const endValue = index === 0 ? 0 : widthsDistanceSum;
+    return endValue + offset;
+  }
+  function onHandlePress(segment, index) {
+    performLayoutAnimation(ANIMATION_DURATION);
+    setActiveSegmentIndex(index);
+    segmentHandler(segment);
+    performSwatchAnimation(index);
+  }
+  function segmentOnLayout(event, index) {
+    const {
+      width,
+      height
+    } = event.nativeEvent.layout;
+    setSegmentsDimensions({
+      ...segmentsDimensions,
+      [index]: {
+        width,
+        height
+      }
+    });
+  }
+  const selectedStyle = usePreferredColorSchemeStyle(styles.selected, styles.selectedDark);
+  const width = segmentsDimensions[activeSegmentIndex]?.width;
+  const height = segmentsDimensions[activeSegmentIndex]?.height;
+  const outlineStyle = [styles.outline, isIOS && styles.outlineIOS];
+  return createElement(View, {
+    style: styles.row
+  }, createElement(View, {
+    style: styles.flex
+  }, addonLeft), createElement(View, {
+    style: [containerStyle, isIOS && styles.containerIOS]
+  }, createElement(Animated.View, {
+    style: [{
+      width,
+      left: positionAnimationValue,
+      height
+    }, selectedStyle, outlineStyle]
+  }), segments.map((segment, index) => {
+    return createElement(Segment, {
+      title: segment,
+      onPress: () => onHandlePress(segment, index),
+      isSelected: activeSegmentIndex === index,
+      key: index,
+      onLayout: event => segmentOnLayout(event, index),
+      accessibilityState: {
+        selected: activeSegmentIndex === index
+      },
+      accessibilityRole: 'button',
+      accessibilityLabel: segment,
+      accessibilityHint: `${index + 1} on ${segments.length}`
+    });
+  })), createElement(View, {
+    style: styles.flex
+  }, addonRight));
+};
+export default SegmentedControls;
+//# sourceMappingURL=index.native.js.map