feat: update excluded columns in feature statistics computation to prevent data leakage

app/training/compute_feature_stats.py

@@ -26,7 +26,7 @@ def compute_stats(csv_path: str | Path, output_path: str | Path) -> None:
         rows = list(reader)
         fieldnames = reader.fieldnames or []
 
-    excluded = {"file_path", "label_int"}
+    excluded = {"file_path", "label_int", "duration_sec", "sample_rate"}
     feature_cols = [c for c in fieldnames if c not in excluded]
 
     stats: dict[str, dict[str, float]] = {}