Recent BambuStudio/OrcaSlicer updates require a bind/detect handshake on
port 3000 before connecting via MQTT/FTP. Without this, slicers cannot
discover or connect to the virtual printer in any mode.
- Add BindServer for server modes (immediate/review/print_queue)
- Add TCPProxy for raw TCP forwarding (proxy mode)
- Update Dockerfile (EXPOSE 3000) and docker-compose.yml (bridge port)
- Add 10 new tests for BindServer protocol and integration