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/lib0/hash/sha256.node.js

@@ -0,0 +1,10 @@
+import { createHash } from 'node:crypto'
+
+/**
+ * @param {Uint8Array} data
+ */
+export const digest = data => {
+  const hasher = createHash('sha256')
+  hasher.update(data)
+  return hasher.digest()
+}