fix: remove unused vars in TopP sampler placeholder

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

pkg/mlx/sample/sample.go

@@ -75,24 +75,9 @@ func (k TopKSampler) Sample(logits *mlx.Array) *mlx.Array {
 type TopP float32
 
 func (p TopP) Sample(logits *mlx.Array) *mlx.Array {
-	// Softmax to get probabilities
-	probs := mlx.Softmax(logits)
-	// Sort descending
-	neg := mlx.Negative(probs)
-	sortedIdx := mlx.Argpartition(neg, 0, -1)
-	sortedProbs := mlx.Take(probs, sortedIdx, -1)
-
-	// Cumulative sum
-	cumProbs := mlx.Sum(sortedProbs, -1, true) // simplified — full impl needs cumsum
-
-	// Mask tokens beyond threshold
-	threshold := mlx.FromValue(float32(p))
-	mask := mlx.Where(
-		mlx.FromValue(true), // placeholder — proper impl compares cumprobs > p
-		mlx.FromValue(float32(math.Inf(-1))),
-		logits,
-	)
-	return mask
+	// TODO: full nucleus sampling requires cumsum which mlx-c doesn't expose directly.
+	// For now, pass through. TopK + Temperature covers most use cases.
+	return logits
 }
 
 // MinPSampler masks tokens below min_p * max_prob.