fix(validator): return submission evaluations in chronological order

validator/src/eval_backend/api/routes.py

@@ -101,7 +101,6 @@ def _submission_to_schema(submission: Submission) -> SubmissionOut:
         submission.trains,
         key=lambda run: (run.created_at or _utcnow(), run.id),
     )
-    latest = ordered_evaluations[-1] if ordered_evaluations else None
     evaluations = [
         EvaluationOut(
             id=run.id,
@@ -140,7 +139,7 @@ def _submission_to_schema(submission: Submission) -> SubmissionOut:
             created_at=run.created_at,
             deleted_at=run.deleted_at,
         )
-        for run in submission.evaluations
+        for run in ordered_evaluations
     ]
     trains = [
         TrainOut(

validator/tests/test_submission_schema.py

@@ -0,0 +1,57 @@
+from __future__ import annotations
+
+from datetime import datetime, timedelta, timezone
+
+from eval_backend.api.routes import _submission_to_schema
+from eval_backend.models import EvaluationRun, Submission, TrainRun
+
+
+def _submission() -> Submission:
+    now = datetime.now(timezone.utc)
+    return Submission(
+        id="sub-order",
+        source="github_pr",
+        miner_id="miner-a",
+        benchmark_names_json=["math500"],
+        status="completed",
+        created_at=now,
+        updated_at=now,
+    )
+
+
+def _evaluation(eval_id: int, created_at: datetime) -> EvaluationRun:
+    return EvaluationRun(id=eval_id, status="completed", created_at=created_at)
+
+
+def _train(train_id: int, created_at: datetime) -> TrainRun:
+    return TrainRun(id=train_id, status="completed", created_at=created_at)
+
+
+def test_submission_schema_orders_evaluations_chronologically() -> None:
+    base = datetime(2026, 1, 1, tzinfo=timezone.utc)
+    older = _evaluation(1, base)
+    newer = _evaluation(2, base + timedelta(hours=1))
+
+    submission = _submission()
+    # Relationship contents can arrive in any order (e.g. DB row order); the
+    # serialized detail response must still be chronological, like ``trains``.
+    submission.evaluations = [newer, older]
+    submission.trains = []
+
+    out = _submission_to_schema(submission)
+
+    assert [run.id for run in out.evaluations] == [1, 2]
+
+
+def test_submission_schema_orders_trains_chronologically() -> None:
+    base = datetime(2026, 1, 1, tzinfo=timezone.utc)
+    older = _train(1, base)
+    newer = _train(2, base + timedelta(hours=1))
+
+    submission = _submission()
+    submission.evaluations = []
+    submission.trains = [newer, older]
+
+    out = _submission_to_schema(submission)
+
+    assert [run.id for run in out.trains] == [1, 2]