Add Expo CNG support and validation example

- Add app.plugin.js entry point for Expo plugin discoverability
- Fix plugin configuration transform to handle redirectUrls properly
- Include plugin directory and entry point in npm package files
- Ensure iOS and Android URL schemes are configured correctly from redirectUrls array

Author: zibs

packages/react-native-app-auth/app.plugin.js

@@ -0,0 +1 @@
+module.exports = require('./plugin');

packages/react-native-app-auth/package.json

@@ -11,6 +11,8 @@
   "files": [
     "android",
     "ios",
+    "plugin",
+    "app.plugin.js",
     "index.d.ts",
     "react-native-app-auth.podspec"
   ],

packages/react-native-app-auth/plugin/index.js

@@ -12,16 +12,27 @@ const {
 const { withAppAuthAppBuildGradle } = require('./android');
 
 const withAppAuth = (config, props) => {
+  // Transform redirectUrls configuration to platform-specific format
+  const transformedProps = props?.redirectUrls ? {
+    ios: {
+      urlScheme: props.redirectUrls[0]?.split('://')[0], // Extract scheme from first URL
+    },
+    android: {
+      appAuthRedirectScheme: props.redirectUrls[0]?.split('://')[0], // Extract scheme from first URL
+    },
+    ...props,
+  } : props;
+
   return withPlugins(config, [
     // iOS
     withBridgingHeader,
     withXcodeBuildSettings,
     withAppAuthAppDelegate,
     withAppAuthAppDelegateHeader,
-    [withUrlSchemes, props],
+    [withUrlSchemes, transformedProps],
 
     // Android
-    [withAppAuthAppBuildGradle, props],
+    [withAppAuthAppBuildGradle, transformedProps],
   ]);
 };