Function priority_label 

pub fn priority_label(
    findings: usize,
    revs_percentile: f64,
    health_band: &str,
) -> &'static str

Classify priority given the three fused signals.

Rules (evaluated in order; first match wins):

• "act-now" — findings > 0 AND revs_percentile >= 0.9 AND health_band == "red"
• "plan" — revs_percentile >= 0.7 OR health_band == "red"
• "note" — everything else