FRE-600: Fix code review blockers

- Consolidated duplicate UndoManagers to single instance
- Fixed connection promise to only resolve on 'connected' status
- Fixed WebSocketProvider import (WebsocketProvider)
- Added proper doc.destroy() cleanup
- Renamed isPresenceInitialized property to avoid conflict

Co-Authored-By: Paperclip <noreply@paperclip.ing>

node_modules/@libsql/isomorphic-ws/README.md

@@ -0,0 +1,16 @@
+# `@libsql/isomorphic-ws`
+
+This package provides `WebSocket` on Node (using `ws`) and in Deno and Cloudflare Workers (using the native `WebSocket`). Supports both CommonJS and ES modules.
+
+```javascript
+import { WebSocket } from "@libsql/isomorphic-ws";
+
+const ws = new WebSocket("ws://localhost:8080");
+ws.onopen = (event) => {
+    ws.send("Hello");
+};
+ws.onmessage = (event) => {
+    console.log(event.data);
+    ws.close();
+};
+```