docs: index Raman holdout source candidates

tests/test_day_level_holdout_validator.py

@@ -1,4 +1,5 @@
 from pathlib import Path
+import json
 from scripts.day_level_holdout_validator import validate
 
 ROOT=Path(__file__).resolve().parents[1]
@@ -8,3 +9,10 @@ def test_empty_preregistered_holdout_remains_honestly_blocked() -> None:
     assert report["status"] == "awaiting_independent_labels"
     assert report["annotation_count"] == 0
     assert report["production_tuning_allowed"] is False
+
+
+def test_raman_source_candidates_are_not_holdout_labels() -> None:
+    payload = json.loads((ROOT / "references/real_case_calibration/raman_vol1_holdout_source_candidates_2026_07_18.json").read_text())
+    assert payload["candidate_count"] >= 20
+    assert all(row["status"] == "needs_independent_normalization" for row in payload["candidates"])
+    assert all("day_level_label" in row["prohibited_uses"] for row in payload["candidates"])