refactor: rebuild birth time rectification agent

scripts/rectification/candidate_feature_service.py

@@ -0,0 +1,23 @@
+from __future__ import annotations
+
+from typing import Any, Sequence
+
+from scripts.active_rectification_event_engine import compute_candidate_static_contexts
+from scripts.rectification.contracts import RectificationRequest
+from scripts.rectification.scoring_service import ALGORITHM_VERSION, sha256
+
+
+def build_candidate_feature_snapshot(
+    request: RectificationRequest,
+    calculation_spec_hash: str,
+    static_contexts: Sequence[dict[str, Any]] | None = None,
+) -> dict[str, Any]:
+    contexts = list(static_contexts) if static_contexts is not None else compute_candidate_static_contexts(request)
+    features = [context["feature"] for context in contexts]
+    return {
+        "calculation_spec_hash": calculation_spec_hash,
+        "algorithm_version": ALGORITHM_VERSION,
+        "candidate_count": len(features),
+        "feature_hash": sha256(features),
+        "features": features,
+    }