Function record 

pub fn record(
    label: &str,
    url: &str,
    request: &Value,
    outcome: &Result<Value>,
    attempts: u32,
    elapsed: Duration,
)

Record one LLM/embedding call outcome. Best-effort: tracing failures never affect the caller (the LLM call result is returned regardless).

• label — call-site kind from post_json_retry (“LLM” / “Anthropic” / “Embedding”).
• url — full endpoint URL (only the host is stored).
• request— the JSON body sent (contains the prompt/input; no API key).
• outcome— the final Result after retries.
• attempts / elapsed — retry count and total wall time.