Function write_trace_bundle 

pub fn write_trace_bundle(
    bundle_dir: &Path,
    system_info: &SystemInfo,
    tui_state_json: Option<&str>,
) -> Result<()>

Write a complete trace bundle directory containing:

• render.trace.jsonl (if render_records is non-empty)
• events.jsonl (if event_records is non-empty)
• system_info.json
• tui_state.json (if state bytes are provided)