chore: import upstream snapshot with attribution

examples/flows/evaluation/eval-basic-maf/aggregation.py

@@ -0,0 +1,23 @@
+"""
+Aggregation function for eval-basic.
+
+Extracted from the original `aggregate.py` PromptFlow node.
+- `@tool` decorator removed (not needed in MAF).
+- `log_metric()` replaced with returning metrics as a dict.
+"""
+
+from typing import Dict, List
+
+
+def aggregate(processed_results: List[str]) -> Dict[str, int]:
+    """Aggregate per-row results into batch-level metrics.
+
+    :param processed_results: List of "Correct"/"Incorrect" strings from all rows.
+    :returns: Dict with metric name → value.
+    """
+    results_num = len(processed_results)
+    correct_num = processed_results.count("Correct")
+    return {
+        "results_num": results_num,
+        "correct_num": correct_num,
+    }