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/entities/src/escape.spec.ts

@@ -0,0 +1,14 @@
+import { describe, it, expect } from "vitest";
+import * as entities from "./index.js";
+
+describe("escape HTML", () => {
+    it("should escape HTML attribute values", () =>
+        expect(entities.escapeAttribute('<a " attr > & value \u00A0!')).toBe(
+            "<a &quot; attr > &amp; value &nbsp;!",
+        ));
+
+    it("should escape HTML text", () =>
+        expect(entities.escapeText('<a " text > & value \u00A0!')).toBe(
+            '&lt;a " text &gt; &amp; value &nbsp;!',
+        ));
+});