chore: add changeset for React Native fix

Author: amondnet

.changeset/fix-react-native-dispatchevent.md

@@ -0,0 +1,9 @@
+---
+"partysocket": patch
+---
+
+Fix React Native/Expo `dispatchEvent` TypeError
+
+Added React Native environment detection to use Node-style event cloning. React Native/Expo environments have both `process` and `document` polyfilled but not `process.versions.node`, which caused browser-style event cloning to be selected incorrectly. Browser-style cloning produces events that fail `instanceof Event` checks in `event-target-polyfill`.
+
+Fixes #257