Function knob_planner_prompt 

pub(crate) fn knob_planner_prompt(
    metric_name: &str,
    goal: &str,
    goal_description: Option<&str>,
    best_value: Option<f64>,
    history: &[RoundRecord],
    attempt_memory: Option<&str>,
    last_verdict_json: &str,
    crate_diff: &str,
    note: Option<&str>,
) -> String

Knob-phase planner prompt: the round context plus an instruction to pick one option to retune (or end the phase). The available options live in the knob-phase system prompt, not here.