Collaborative Editing in Blazor Diagram Using SignalR and Redis

SignalR and Redis enable real-time collaborative editing in Blazor Diagram by broadcasting delta payloads from HistoryChanged events through a SignalR hub. The implementation uses optimistic concurrency with version tracking (userVersion/serverVersion) to detect and reject conflicting edits. Redis serves as a backplane for scaling across multiple server instances, while SetDiagramUpdatesAsync applies remote changes. The approach includes conflict detection by tracking modified element IDs and rejecting stale updates when overlaps occur.