fix: configure Metro for monorepo local development in expo-example

Without watchFolders, nodeModulesPaths, and blockList, Metro cannot
resolve the symlinked @intercom/intercom-react-native package when
developing locally from examples/expo-example. This caused a cascade
of errors: unresolved modules, duplicate React Native copies, and
SyntaxError from stale dependencies in the library root's node_modules.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: Rosie-Kennelly-1

examples/expo-example/metro.config.js

@@ -1,7 +1,17 @@
+const path = require('path');
 const { getDefaultConfig } = require('expo/metro-config');
 const { withNativeWind } = require('nativewind/metro');
 
+const libraryRoot = path.resolve(__dirname, '..', '..');
+
 const config = getDefaultConfig(__dirname);
 config.resolver.unstable_enableSymlinks = true;
+config.watchFolders = [libraryRoot];
+config.resolver.nodeModulesPaths = [
+  path.resolve(__dirname, 'node_modules'),
+];
+config.resolver.blockList = [
+  new RegExp(path.resolve(libraryRoot, 'node_modules') + '/.*'),
+];
 
 module.exports = withNativeWind(config, { input: './global.css' });