// pure function — deterministic, no side-effects
function evaluateApexSwing(
  s: Signal, p: ApexParams
): Evaluation {
  if (s.regime === 'bear')
    return { action: 'HOLD_SKIP', reason: 'defense' }

  const entry = s.trend > 0 && s.pullback < p.dip
  if (entry && s.mlAgree)
    return {
      action: 'BUY',
      confidence: s.score,
      reason: `apex · dip ${s.pullback}`,
    }
  return { action: 'HOLD_SKIP', reason: 'no setup' }
}