Function propose_fact_draft 

pub fn propose_fact_draft(
    prompt: &str,
    encode: &dyn Fn(&str) -> Vec<u32>,
) -> Draft

Draft tokens from the quant-graph fact table (repair text encoded by caller).

encode should be the model tokenizer (encode or chat-aware). Returns empty when no fact matches the prompt. Uses empty-answer probe: if needles match and the (empty) answer is not yet grounded, draft the repair string for verify.