Add VNC console WebSocket endpoints for Docker and QEMU nodes:
- Add /console/vnc WebSocket endpoint to compute API (Docker & QEMU)
- Add /console/vnc WebSocket endpoint to controller API
- Implement start_vnc_websocket_console() in BaseNode
- Forward VNC WebSocket traffic between controller and compute layers
The implementation provides bidirectional WebSocket to TCP forwarding
for VNC protocol (RFB) connections, allowing browser-based VNC console
access to containers and VMs.
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
