[Remote rendering 5.2] Replace local render window with pvserver connection #34

📝 Description of the feature

Implement ParaView's pvserver client connection so RemoteRenderer renders against pvserver instead of the local render-window stand-in used by the initial spike, then remove that stand-in.

Re-verify the Phase 4 behaviour (streaming, per-part state, camera interaction, coalescing, connect/reconnect, live refresh) against the real ParaView server backend.

Acceptance Criteria

Remote rendering behaviour holds with pvserver as the backend.

💵 Business Value

No response

🔗 Useful links and references

No response