Bug Description

On the third message in a fresh NemoClaw installation, system runtime instructions are being displayed to the user in the chat interface. The <nemoclaw-runtime> block containing sandbox policy information is rendered in the UI instead of being filtered out.

Steps to Reproduce

1. Fresh NemoClaw install using curl -fsSL https://www.nvidia.com/nemoclaw.sh | bash
2. Complete onboarding with Nemotron 3 Super 120B via Local Ollama
3. Access Web UI via SSH tunnel: ssh -L 18789:127.0.0.1:18789 user@host
4. Send 2-3 messages in the chat interface
5. On approximately the third message, the system runtime instructions appear in the UI

Expected Behavior

System messages and runtime instructions should be filtered out before being displayed to the user.

Actual Behavior

The following content is displayed in the chat UI:

<nemoclaw-runtime> You are running inside OpenShell sandbox "openclaw" via NemoClaw. Treat this as a sandboxed environment, not unrestricted host access. Network policy: - outbound network is deny-by-default; assume no arbitrary internet access - blocked requests can return proxy 403 and may need operator approval or policy changes Filesystem policy: - filesystem/process access is sandboxed; do not assume host-level access Behavior: - Do not claim unrestricted host or internet access. - if access is blocked, say it is blocked and ask the operator to adjust policy or approve it in OpenShell </nemoclaw-runtime>

Environment

• NemoClaw Version: Latest (installed 2026-05-21)
• OpenShell Version: 0.0.39
• Model: nemotron-3-super:120b (Local Ollama)
• Platform: DGX Spark (GB10), Ubuntu 24.04, ARM64
• Access Method: Web UI via SSH tunnel

Impact

This exposes internal system prompts to users on their third interaction with a fresh install, suggesting fragile message boundary handling or UI filtering logic.

Additional Context

• The user asked: "What's the difference between nemoclaw and openclaw?"
• The runtime message appeared after the agent's response was completed
• No errors visible in browser console
• Sandbox logs show normal operation, no specific errors related to message rendering