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>

server/websocket/index.ts

@@ -23,12 +23,12 @@ export async function startServer(config: ServerConfig) {
       return { userId: 'anonymous', projectId: 'default' };
     }
 
-    // Simple JWT verification (in production, use jsonwebtoken library)
     try {
-      const decoded = JSON.parse(Buffer.from(token.split('.')[1], 'base64').toString());
+      const jwt = require('jsonwebtoken');
+      const decoded = jwt.verify(token, jwtSecret);
       return {
-        userId: decoded.userId,
-        projectId: decoded.projectId,
+        userId: (decoded as any).userId,
+        projectId: (decoded as any).projectId,
       };
     } catch (error) {
       throw new Error('Invalid JWT token');