docs(expo): document @clerk/expo config plugin options

docs/reference/expo/native-components/overview.mdx

@@ -24,7 +24,7 @@ Native components require:
 
 - A [development build](https://docs.expo.dev/develop/development-builds/introduction/) (`npx expo run:ios` or `npx expo run:android`), as these components are not available in Expo Go.
 
-- The `@clerk/expo` plugin configured in your `app.json` file:
+- The `@clerk/expo` plugin configured in your `app.json` file. See the [available plugin options](#expo-plugin-options).
 
   ```json {{ filename: 'app.json' }}
   {
@@ -36,6 +36,42 @@ Native components require:
 
 - If using social connections, you must register your native application credentials in the Clerk Dashboard. See the [Sign in with Google](/docs/guides/configure/auth-strategies/sign-in-with-google) and [Sign in with Apple](/docs/guides/configure/auth-strategies/sign-in-with-apple) guides for setup steps.
 
+### Expo plugin options
+
+The plugin accepts the following options:
+
+<Properties>
+  - `appleSignIn`
+  - `boolean`
+
+  Whether to add the `com.apple.developer.applesignin` entitlement. Set to `false` if your app does not use Apple Sign In. Defaults to `true`.
+
+  ---
+
+  - `keychainService`
+  - `string`
+
+  Custom keychain service identifier. Required if you need extension targets (widgets, App Clips, Watch) to share the keychain with the main app.
+</Properties>
+
+#### Example
+
+```json {{ filename: 'app.json' }}
+{
+  "expo": {
+    "plugins": [
+      [
+        "@clerk/expo",
+        {
+          "appleSignIn": false,
+          "keychainService": "com.example.myapp"
+        }
+      ]
+    ]
+  }
+}
+```
+
 ## How it works
 
 The native components handle authentication through the native Clerk SDKs ([clerk-ios](https://github.com/clerk/clerk-ios) and [clerk-android](https://github.com/clerk/clerk-android)). When authentication completes, the session is automatically synchronized to the JavaScript SDK: